# Overview of Graphs

This overview will start with a brief summary of the process involved in creating a graph, then will discuss the terminology used in this document, will present the components of a graph, and present the hierarchy of the components used in to configure the graphs.

## The Graph Creation Process

The process of graph creation involves several steps each of which requires the user to understand clearly what they intend to do. This outline is presented to help users understand the subsequent discussion in this document.

## Outline of the procedure to create a graph.

1. ## Data entry.

   Before a graph can be created, the data must be entered into a workbook.

2. ## (Optional) Data pre-selection.

   As explained in sect-graphs-preselect, it is possible to pre-select the data and have &gnum; correctly assign the cell contents into series names, category labels and data values. This process can only be understood once the rest of the graph creation process has been mastered so the discussion of pre-selecting data is left until the end of this section.

3. ## Opening the graph guru

   The Graph Guru can be opened in two ways. It can be opened by clicking on the Graph Guru button, An image of the toolbar graph guru button. , which is on the standard toolbar immediately to the left of the zoom box. Alternatively the Graph Guru can be opened by using, in the Insert menu, the Chart menu item.

4. ## Configuring the graph

   The Graph Guru provides the user with a large number of options to configure the graph, its charts and the plots. The first panel provides a way to select the plot type, sub-type and, for some types, a style. The second panel allows the user to configure each element of the graph. When the configuration is complete, the guru is dismissed by clicking the OK button. This step will be explained in detail in sect-graphs-graphguru-navigating, below.

5. ## Inserting the graph

   Finally, the graph is inserted into the worksheet like any other graphical element, as was explained in sect-graphical-overview-adding.

## On Terminology

The terminology used for describing the components of data graphs is confusing because graphs use many components and the words are applied arbitrarily to each component. For example, the words "graph", "chart", and "plot" could be used interchangeably but in &gnum; these words are used as explained below.

The term 'graph' will be used, in this documentation, to refer to the entire graphical element placed on the worksheet. A graph has an outline and a background, may have one or more titles, and will have at least one 'chart'.

The term 'chart' will be used to denote an intermediate level element which has an outline and a background, may have one or more titles, may have a legend and will have at least one 'plot'. To support the plot, the chart may have a 'grid' area behind the plotted data, and have one or more axes.

Each 'plot' will be defined to be of a particular type when it is created. Plots will have one or more 'series' of data values which will define the magnitude of the values of to be plotted and may define a number of other related values including errors in the x and y directions.

This terminology can be used to describe in detail the components of a graph in &gnum;. fig-graph-components presents the components of a graph.

## The Components of Graphs

### The components of &gnum; graphs

This screenshot depicts a graph in &gnum; and describes all of the components.

This screenshot presents several of the major components of &gnum; graphs. These components will be presented next in their containment hierarchy. The hierarchy is used in the Graph Guru to organize the components so a user can change all the preferences.

## The Graph Component Hierarchy

The components that make up a graph in &gnum; are arranged in a hierarchy with all the configurable options of the graph assigned as properties to one of the components in the hierarchy.

### The hierarchy of components and their properties

This figure includes an image of the graph hierarchy presented by the graph guru along with text descriptions of each component and of their properties.

The hierarchy of graph component elements and the associated properties. In this case, the element 'X-Axis2' is selected.

In &gnum;, Graphs are the top level element containing all the other components. Graphs have two properties related to the style of the background rectangular panel, its fill and its outline. Graphs can hold one or more titles and one or more charts.

Titles have the same properties related to their background rectangular panel, the fill and outline, have properties related to the text, the font type, style, and size, and have the text data that will be the title itself.

Charts have the same properties related to the background rectangular panel and can contain a number of other components including their own titles, a legend, plot accessories and plots.

Legends have the same properties related to their background rectangular panel and also have the properties related to the font in which the name of each series will be added to the legend, the font type, style, and size.

Certain plot types require accessory components such as the elements related to the creation of a Cartesian coordinate system. Charts which include one or more plots of this kind will have a Grid and may have X (horizontal) and Y (vertical) axes.

Grids are the background of Cartesian plots and have the properties determining the fill of this area and the line pattern displayed behind the plotted series.

Axes have properties related to the outer bounds of the axis, the style of the line drawn for the axis, the font style of the markers along the axis, detail properties of the tics and other markers on the axis, and the number format of the axis markers.

Axis labels share the same properties related to the style of their background rectangular panel, including the fill and outline properties, have properties related to the style of the font used for the text, including the font type, style and size, and the data contents of the text used to label the axis.

The properties of each type of plot, and of the data series they contain, vary depending on the actual type of the plot. For instance, the values of a data series which are plotted as a pie plot will not have any associated error values, whereas values plotted as columns could be associated to Y-error values and values plotted as an XY scatterplot could be associated with error values in both the X and the Y direction. Obviously, these different plot types will require different options. The options associated with each specific plot type will be discussed below, in sect-graphs-elementProperties.

## The Graph Guru

All graphs in &gnum; are created using the Graph Guru which is a complex dialog that allows for detailed customization of each graph.

## The components of the Graph Guru

The Graph Guru consists of two panels which appear sequentially. The first panel allows the user to select the type of the plot, and possibly a sub-type and a style. The second panel provides a way to configure the style formats of each component of the final graph. fig-graphguru-panels shows the different areas of the two panels of the Graph Guru.

### The two panels of the Graph Guru

This screenshot depicts the two panels of the graph guru.

The different parts of each panel of the Graph Guru have been shaded with boxes of different colors and labeled with a letter in fig-graphguru-panels. The purpose of each of these sections will be explained below:

## The components of the two panels

A - The Plot Type Selection Area

- This area lists the different types of plots which can be contained within the graph. The desired plot type can be selected simply by placing the mouse cursor over the desired type and clicking with the primary mouse button. The blue highlight indicates the currently selected type.

B - The Preview Area.

- This area shows a preview of the currently selected plot type/sub type combination using the default settings for this type of plot.

C - The Plot Subtype Area.

- This area presents a number of icons which change depending on the plot type that has been selected. Certain icons represent plot sub-types, for example, distinguishing plots with columns that are side by side from plots with stacked columns. Other icons represent different plot styles, for example distinguishing line plots in which each data point is labeled with a graphical symbol from line plots where data points do not have any symbol. The highlight box around one icon indicates which icon is currently chosen.

  Hovering the mouse pointer over one of these icons causes a description of the plot type to be shown next to the icon.

D - The First Panel Navigation Buttons

- These buttons enable the user to navigate through the Graph Guru.

  The Help Button

- The Help button should cause this section of the manual to open.

The Cancel Button

- The Cancel button will dismiss the Graph Guru and return the user to the &gnum; worksheet.

The Forward Button

- The Forward button will dismiss the first panel of the Graph Guru and open up the second panel.

The Insert Button

- The Insert button will dismiss the Graph Guru and allow users to insert the graph, as it is currently defined, into the worksheet. The resulting graph may not include any plots or data but it can be modified subsequently using the context menu's Properties menu entry.

E - The hierarchy tree of graph components

- This area allows the user to navigate the hierarchy of graph components. The components are arranged in a tree with nodes indicated by arrowheads. Components can be selected by clicking on the component name with the mouse pointer and nodes can be expanded or collapsed by clicking on the arrowheads. The selection of different components in this area will cause different property options to be displayed in area J since each component in the hierarchy has its own specific properties.

  Immediately below the hierarchy are buttons that allow a user to modify the hierarchy of components by adding components with the Add button or by removing components with the Delete button. The Order allows the user to change the stacking order of charts, moving them up or down, or of data series, moving them toward the front or back.

F - The preview area

- This area shows a preview of the graph as it will look if the user clicks on the Insert or Apply at the bottom of the panel, in area H.

G - The component properties selection area.

- This area allows the user to change the graph by modifying the properties of the component that is selected (highlighted in blue) in area E. For components which have multiple properties these may be grouped into related sets and placed on different tabs. By clicking on the tabs at the upper left, a user can access the properties in each set.

H - The second panel navigation buttons

- If the guru is opened to create a new graph the buttons in this are act in the same way as the buttons in the first panel, in area D except that the Forward is now a Back and takes the user back to the first panel.

  If the guru is opened to modify an existing graph the following buttons are shown (as in the screenshot fig-graphguru-panels).

  The Help Button

- The Help button should cause this section of the manual to open.

The Cancel Button

- The Cancel button will dismiss the Graph Guru and return the user to the &gnum; worksheet, leaving the graph unchanged.

The Apply Button

- The Apply button will dismiss the Graph Guru and apply the changes to the current graph.

K - The panel rearrangement handles

- These triple dots in various places of the two panels of the graph guru indicate that the mouse can be used to change the size of the different areas. These handles can be used by placing the mouse pointer above a handle, clicking and holding with the primary mouse button, then dragging the handle to a new position, and then releasing the mouse button.

## Navigating the graph guru

Graphs in &gnum; are created using the Graph Guru. The process involved in using this 'guru' essentially follows the alphabetical labels presented in fig-graphguru-panels.

## The Graph Creation Process

1. ## Data Pre-selection

   Advanced users generally start by pre-selecting at least some of the data they will use in their plots. However, this step requires a complete understanding graphs and this step is not described here. sect-graphs-preselect will explain data preselection once the rest of the graphing process has been explained.

2. ## Launching the Graph Guru

   The Graph guru can be started in two ways. One way to start the Graph Guru is to click, with the primary mouse button, on the toolbar graph button, The icon on the toolbar button which starts the graph guru. . Another way is to select, from the Insert menu, the Chart... menu item. Both approaches will launch the Graph Guru.

3. ## Selecting the plot type, sub-type, and style.

   The Graph guru opens to the first of two panels. The areas of this panel are shown in the left hand side of fig-graphguru-panels. This panel enables the user to select the type of the first plot in the chart, and its sub-type and style. To make a graph with multiple plots, a user should start by selecting the first plot; subsequent plots can be added later.

   1. ## Picking the plot type

      The first area, area A, provides a list of the plot types. The user can pick one of the types by placing the mouse pointer on top of that appropriate entry in the list and clicking the primary mouse button. The blue highlight indicates which plot type has been chosen. The characteristics of the different plot types are explained extensively in sect-graphs-overview-types.

   2. ## Picking the plot sub-type and style

      The second area of the first panel of the Graph Guru, labeled B in fig-graphguru-panels, presents one or more icons. The icons presented in this area will change depending on what plot type is highlighted in area A. The icons provide a way to select a sub-type of plot, for example, the icons for the column plot type provide the choice between plotting columns of each data series side-by-side or plotting these columns stacked upon each other. These icons may also provide a way to quickly select different styles for the plot type, for example the icons for the line type provide a choice between plotting a simple line or placing markers at the points along the line. The sub-type cannot be changed in the next panel of the Graph Guru without deleting the plot and creating a new one. However, the style choices can be altered in the next panel. The meaning of each of these icons is explained in sect-graphs-overview-types below grouped by plot type. If data has been pre-selected, clicking on the Show Sample will present a preview of the plot type in area B.

   3. ## Moving to the next panel

      Once a plot type has been chosen in area A and an icon selected in area B, the first panel has been completed. Clicking on the Forward button will dismiss the first panel of the Graph Guru and bring up the second panel.

4. ## Configuring the plot

   The second panel of the Graph Guru enables users to configure the plot. This includes determining the values which will actually be plotted, adding titles to various components, labels to the data series, names to data categories, and changing the appearance of the different components.

   The simplest way both to learn the hierarchy of components in &gnum; graphs and to understand the properties which can be changed for each component is to work sequentially through all of the components while both noting the components which can be added, listed in the drop down menu when the Add button is pressed, and observing the properties of the component which can be altered, shown in the lower part of the panel, the area labeled J in fig-graphguru-panels. Each component in the hierarchy can be selected in turn using the complete tree of all the components presented in the top leftmost area, labeled F. Components can be selected by placing the mouse pointer over their name in this tree and then clicking with the primary mouse button. The currently selected component is indicated by the blue highlight on that line. Changing the selected component will also change the properties listed in area J. Tree nodes, indicated by arrowheads in front of the name of a component, can be expanded or collapsed with alternative mouse clicks.

   The second panel of the Graph Guru only allows two types of actions to be performed: the hierarchy of component elements can be modified or the properties of an element can be altered.

   ##

   Changing the component elements

5. The component elements of the graph can be changed using the buttons in area G. Elements can be added, deleted or re-ordered.

   ##

   Adding component elements

6. An element can be added by selecting the parent element in the hierarchy presented in area F and then clicking and holding the Add button. This action will reveal a drop down list including all the possible elements that can be added. By moving the mouse pointer onto the drop down list and releasing the mouse button while the pointer is over an element, that element will be added. To add a plot to a chart, it is necessary to navigate into the sub-menu to select the plot type and then into that sub-menu to select a plot sub-type or style in a process that mimics the process of selecting a plot discussed above.

Deleting component elements

- An element can be deleted by selecting the element in the hierarchy presented in area F, and then clicking the Delete button below the hierarchy.

Re-ordering component elements

- The order of some of the elements can be interchanged using the Order button below the element hierarchy. For example, if an element has two titles, the order of the titles could be swapped. Similarly the vertical order of charts can be interchanged. The effect on plots and series is different. For those elements, the order button changes the stacking order in the front to back dimension. For example, if a chart has a bar plot and a line plot, the order button will change which of the two plots is visible in front of the other.

Configuring the properties of the Element

- The bottom area of the second panel, area J in fig-graphguru-panels, allows the user to configure the properties of each element in the hierarchy. When there are many properties, they will be grouped into similar sets and placed on different tabs. The detailed explanation of how to configure each property of each element will be explained in sect-graphs-elementProperties below.

Once the plot is sufficiently configured, it can be placed on the worksheet to assess its appearance. The user can return to this panel of the Graph Guru using the context menu on the graph. The Graph Guru is dismissed by clicking on the OK button.

- ## Place the graph

  After exiting the Graph Guru, the user must place the graph on a worksheet. Immediately after exiting the Graph Guru, the mouse pointer will have changed to the thin cross-hair cursor. The user can place the graph by moving the pointer over the worksheet and clicking once with the primary mouse button. Alternatively, the user can place and size the graph by determining two of the corners of the graph. This is done by moving the pointer onto the worksheet to the first corner, clicking and holding the primary mouse button, dragging the mouse pointer to the opposite corner and releasing the mouse button.

- ## Modifying an existing graph

  A graph which has already been created can be modified by clicking on the graph with one of the secondary mouse buttons in order to invoke the context menu and then selecting the Properties menu entry. This will cause the second panel of the Graph Guru to appear which will enable the user to make any desired modifications. The use of the context menu was discussed in sect-graphical-overview-contextmenu.

- ## Deleting a graph

  A graph which has been made can be deleted by invoking the context menu and selecting the Delete menu item.

## Plot Types

&gnum; graphs can include any of the plot types presented below. The section for each type explains the overall concept of the plot, gives an example, explains the data required for the plot type, and explains the icons in the Graph Guru which allow setting the plot sub-type and style.

## Area Plots

Area plots present the numeric values of categorical data with the data values of each series connected by a line and the area below the line shaded. This type is directly analogous to the line plot type. Sequential data values are considered to belong to different categories and are plotted along the horizontal axis at equally spaced intervals. The data values from different series are assigned to these categories based on the position of the value in the series, for example, the second data value taken from each series all share one category. The data values are plotted along the vertical (Y) axis according to their numeric value and the particular sub-type chosen for the area plot.

Area plot sub-types provide three options for relating the values from different data series. The first sub-type plots each series independently with the data value determining the vertical distance between each point and the horizontal axis. The second sub-type plots the series stacked on each other in a cumulative fashion with the data value of each series determining the vertical distance from the point to the sum of the values in all the previous series. For example, if the first series starts with values `{3.9, 4.2, ...}`, the second series with values `{1.2, 3.5, ...}`, and the third series with values `{3.1, 1.9, ...}`, then the point value for the second element of the third series will be plotted at 9.6 (since `9.6=4.2+3.5+1.9`) along the vertical axis. The third sub-type plots each series based on the proportional contribution of the value to the total of all values in that category. Using the example above, the three values would be plotted at 0.4375, 0.8020, and 1 because the intervals between zero and each of these numbers is `0.4375=4.2/(4.2+3.5+1.9)` for the first, `0.3645...=3.5/(4.2+3.5+1.9)` for the second, and `0.1979...=1.9/(4.2+3.5+1.9)` for the third, although, by default, these numbers are presented as percentages on the vertical (Y) axis.

Area plots do not have any pre-defined styles.

### An example of area plots

A screenshot of a worksheet with a data table and a graph containing an area plot.

This screenshot shows a table of data and three area plots. The data consist of three series organized by row and starting with the words "Widgets", "Gadgets", and "Lumpets". Each of these series has values in five categories. The three graphs illustrate the three sub-types of area plots, with the series plotted independently in the left plot, stacked in the middle plot, and proportionately stacked in the right plot.

Each series in area plots can include three main elements and two error elements, although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The 'Label' element is shared by all of the series. The legend added to an area plot identifies the different series, by default using the entries of the 'Name' element of each series. The two error elements include a list for errors in the positive direction and one for errors in the negative direction.

## The data in each area plot series

Element | Type | Example
Name | A single textual element labeling the data series. These will be used in the legend which may be displayed with the area plot. | {"Widgets"}
Value | A series of numeric values. | {1293, 2502, 3297, 1100, 2487}
Label | A series of textual elements labeling each value. Generally, this series will have as many entries as there were in the "Value" series. These entries are shared by all the series in the area plot. | {"North", "South", "Central", "East", "West"}
Error (+) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
Error (-) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}

Area plots provide three icons to choose one of the three area plot sub-types.

## Area plot sub-type and style options.

The icon for an area plot of the sub-type with independent, overlapping areas.

- The icon for an area plot of the sub-type with independent, overlapping areas.

The icon for an area plot of the sub-type with stacked areas.

- The icon for an area plot of the sub-type with stacked areas.

The icon for an area plot of the sub-type with stacked, proportionate areas.

- The icon for an area plot of the sub-type with stacked, proportionate areas.

## Bar Plots

Bar plots present the numeric values of categorical data with the data values of each series represented as a horizontal bar. Sequential data values are considered to belong to different categories and are plotted along the vertical axis at equally spaced intervals. The data values from different series are assigned to these categories based on the position of the value in the series, for example, the second data value taken from each series all share one category. The data values are plotted along the horizontal (X) axis as bars of different lengths and positions depending on the numeric content of the data value and the particular sub-type chosen for the bar plot.

Bar plot sub-types provide three options for relating the values from different data series. The first sub-type plots each series independently in adjacent bars, each of which is tied to the vertical axis and has its length determined by the numeric content of the data value. The second sub-type plots each series as a horizontally stacked set of bars with the horizontal length of each element determined by the numeric content of the data value and the position of the bar determined by the position of the element in the data series. For example, if the first series starts with values `{3.9, 4.2, ...}`, the second series with values `{1.2, 3.5, ...}`, and the third series with values `{3.1, 1.9, ...}`, then the third bar will be plotted ranging from 7.7 to 9.6, since `7.7=4.2+3.5` and `9.6=4.2+3.5+1.9`. The third sub-type plots each series as a horizontally stacked set of bars scaled to the total all the numeric values in that category. Using the example above, the three bars would range from 0 to 0.4375, from 0.4375 to 0.8020, and from 0.8020 to 1 respectively because the intervals are the proportional contribution of each data value to the total, i.e. `0.4375=4.2/(4.2+3.5+1.9)` for the first, `0.3645...=3.5/(4.2+3.5+1.9)` for the second, and `0.1979...=1.9/(4.2+3.5+1.9)` for the third. By default, these numbers are presented as percentages on the horizontal (X) axis.

Bar plots do not have any pre-defined styles.

### An example of bar plots

A screenshot of a table of data and three bar plots made using those data.

This screenshot shows a table of data and three bar plots. The data consist of three series organized by row and starting with the words "Widgets", "Gadgets", and "Lumpets". Each of these series has values in five categories. The three graphs illustrate the three sub-types of bar plots, with the series plotted independently in the left plot, stacked in the middle plot, and proportionately stacked in the right plot.

Each series in bar plots can include three main elements and two error elements, although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The 'Label' element is shared by all of the series. The legend added to a bar plot identifies the different series, by default using the entries of the 'Name' element of each series. The two error elements include a list for errors in the positive direction and one for errors in the negative direction.

## The data in each bar plot series

Element | Type | Example
Name | A single textual element labeling the data series. These will be used in the legend which may be displayed with the bar plot. | {"Widgets"}
Value | A series of numeric values. | {1293, 2502, 3297, 1100, 2487}
Label | A series of textual elements labeling each value. Generally, this series will have as many entries as there were in the "Value" series. These entries are shared by all the series in the bar plot. | {"North", "South", "Central", "East", "West"}
Error (+) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
Error (-) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}

Bar plots provide three icons to choose one of the three bar plot sub-types.

## Bar plot sub-type and style options.

The icon for a bar plot of the sub-type with independent, adjacent bars.

- The icon for a bar plot of the sub-type with independent, adjacent bars.

The icon for a bar plot of the sub-type with horizontally stacked bars.

- The icon for a bar plot of the sub-type with horizontally stacked bars.

The icon for a bar plot of the sub-type with horizontally stacked, proportionately scaled bars.

- The icon for a bar plot of the sub-type with horizontally stacked, proportionately scaled bars.

## Bubble Plots

The data values from three series of equal length are plotted on the Cartesian (X-Y) plane, the value from the first series determining the position of the plotted symbol center along the X axis, the value from the second series determining the position of the plotted symbol center along the Y axis, and the value of the third series determining the radius of the circle plotted. Each triplet of series can be plotted with different symbols but the data values of any series can be shared.

### An example of a bubble plot

A screenshot of a worksheet with two series of data, each with three lists, and of the resulting bubble plot.

This screenshot shows a worksheet with a table of data with two series, each with three lists of numeric values. The screenshot also shows a bubble plot made from these two series.

Each series in a bubble plot can include four main components and four optional error components. The series may have a name, a single text value which will identify the series in the graph guru and in any legend attached to the chart. The series must have two lists of quantitative values, a list of X values and a list of Y values, which must have an equal number of elements. The series must also have a list, with the same number of elements, whose values will determine the size of the circles drawn at each point. The series may have lists of error components for the X values or the Y values and for positive or negative errors.

## The data in each bubble series

Element | Type | Example
Name | A single textual element labeling the data series. | {"Series1"}
X | A list of numeric values, which will place the values along the horizontal axis. | {14.5, 2.8, 11.8, 5.7, 8.2}
Y | A second list of numeric values, which will place the values along the vertical axis. | {154, 29, 63, 90, 107}
Bubble | A series of numeric values, which will determine the size of each circle drawn at the points. | {45, 54, 34, 23, 37}
X Error (+) | A list of numeric values with as many elements as there were in the 'X' list. These values can be in the same units as the numeric values in the 'X' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
X Error (-) | A list of numeric values with as many elements as there were in the 'X' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}
Y Error (+) | A list of numeric values with as many elements as there were in the 'Y' list, and therefore in the 'X' list. These values can be in the same units as the numeric values in the 'Y' list, can be proportions or can be proportions multiplied by one hundred. | {0.09, 0.11, 0.10, 0.12, 0.09}
Y Error (-) | A list of numeric values with as many elements as there were in the 'Y' list, and therefore in the 'X' list. These values can be in the same units as the numeric values in the 'Y' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.09, 0.08, 0.11, 0.11}

Bubble plots have a single icon for the plot style.

## The icon for bubble plots

The icon for a bubble plot.

- The icon for a bubble plot.

## Colored XY Plots

Work in Progress

## Column Plots

Column plots present the numeric values of categorical data with the data values of each series represented as a vertical column. Sequential data values are considered to belong to different categories and are plotted along the horizontal axis at equally spaced intervals. The data values from different series are assigned to these categories based on the position of the value in the series, for example, the second data value taken from each series all share one category. The data values are plotted along the vertical (Y) axis as columns of different heights and positions depending on the numeric content of the data value and the particular sub-type chosen for the column plot.

Column plot sub-types provide three options for relating the values from different data series. The first sub-type plots each series independently in adjacent bars, each of which is tied to the horizontal axis and has its height determined by the numeric content of the data value. The second sub-type plots each series as a vertically stacked set of columns with the vertical height of each element determined by the numeric content of the data value and the position of the column determined by the position of the element in the data series. For example, if the first series starts with values `{3.9, 4.2, ...}`, the second series with values `{1.2, 3.5, ...}`, and the third series with values `{3.1, 1.9, ...}`, then the third column will be plotted ranging from 7.7 to 9.6, since `7.7=4.2+3.5` and `9.6=4.2+3.5+1.9`. The third sub-type plots each series as a vertically stacked set of columns scaled to the total all the numeric values in that category. Using the example above, the three columns would range from 0 to 0.4375, from 0.4375 to 0.8020, and from 0.8020 to 1 respectively because the intervals are the proportional contribution of each data value to the total, i.e. `0.4375=4.2/(4.2+3.5+1.9)` for the first, `0.3645...=3.5/(4.2+3.5+1.9)` for the second, and `0.1979...=1.9/(4.2+3.5+1.9)` for the third. By default, these numbers are presented as percentages on the vertical (Y) axis.

Column plots do not have any pre-defined styles.

### An example of column plots

A screenshot of a table of data and three column plots made using those data.

This screenshot shows a table of data and three column plots. The data consist of three series organized by row and starting with the words "Widgets", "Gadgets", and "Lumpets". Each of these series has values in five categories. The three graphs illustrate the three sub-types of column plots, with the series plotted independently in the left plot, stacked in the middle plot, and proportionately stacked in the right plot.

Each series in column plots can include three main elements and two error elements, although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The 'Label' element is shared by all of the series. The legend added to a column plot identifies the different series, by default using the entries of the 'Name' element of each series. The two error elements include a list for errors in the positive direction and one for errors in the negative direction.

## The data in each column plot series

Element | Type | Example
Name | A single textual element labeling the data series. These will be used in the legend which may be displayed with the column plot. | {"Widgets"}
Value | A series of numeric values. | {1293, 2502, 3297, ,1100, 2487}
Label | A series of textual elements labeling each value. Generally, this series will have as many entries as there were in the "Value" series. These entries are shared by all the series in the column plot. | {"North", "South", "Central", "East", "West"}
Error (+) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
Error (-) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}

Column plots provide three icons to choose between three plot sub-types.

## Column plot sub-type and style options.

The icon for pie plot of style with joint slices.

- The icon for pie plot of style with joint slices.

The icon for pie plot of style with joint slices.

- The icon for pie plot of style with joint slices.

The icon for pie plot of style with joint slices.

- The icon for pie plot of style with joint slices.

## Contour Plots

Work in Progress

## DropBar Plots

Work in Progress

## Line Plots

Line plots present the numeric values of categorical data with the data values of each series connected by a line. Sequential data values are considered to belong to different categories and are plotted along the horizontal (X) axis at equally spaced intervals. The data values from different series are assigned to these categories based on the position of the value in the series, for example, the second data value taken from each series all share one category. The data values are plotted along the vertical (Y) axis according to their numeric value and the particular sub-type chosen for the line plot.

Line plot sub-types provide three options for relating the values from different data series. The first sub-type plots each series independently with the data value determining the vertical distance between each point and the horizontal axis. The second sub-type plots the series stacked on each other in a cumulative fashion with the data value of each series determining the vertical distance from the point to the sum of the values in all the previous series. For example, if the first series starts with values `{3.9, 4.2, ...}`, the second series with values `{1.2, 3.5, ...}`, and the third series with values `{3.1, 1.9, ...}`, then the point value for the second element of the third series will be plotted at 9.6 (`9.6=4.2+3.5+1.9`) along the vertical axis. The third sub-type plots each series based on the proportional contribution of the value to the total of all values in that category. Using the example above, the three values would be plotted at 0.4375, 0.8020, and 1 because the intervals between zero and each of these numbers is `0.4375=4.2/(4.2+3.5+1.9)` for the first, `0.3645...=3.5/(4.2+3.5+1.9)` for the second, and `0.1979...=1.9/(4.2+3.5+1.9)` for the third, although, by default, these numbers are presented as percentages on the vertical (Y) axis.

Two styles are available by default for line plots. In the first no markers are placed on the value of the point whereas in the second a point marker is added wherever the points are plotted.

### An example of line plots

A screenshot of a line plot and the data necessary to generate the plot.

This screenshot shows a table of data and three line plots. The data consist of three series organized by row and starting with the words "Widgets", "Gadgets", and "Lumpets". Each of these series has values in five categories. The three graphs illustrate the three sub-types of line plots, with the series plotted independently in the left plot, stacked in the middle plot, and proportionately stacked in the right plot.

Each series in line plots can include three main elements and two error elements, although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The 'Label' element is shared by all of the series. The legend added to a line plot identifies the different series, by default using the entries of the 'Name' element of each series. The two error elements include a list for errors in the positive direction and one for errors in the negative direction.

## The data in each line plot series

Element | Type | Example
Name | A single textual entry labeling the data series. These will be used in the legend which may be displayed with the line plot. | {"Widgets"}
Value | A list of numeric values. | {1293, 2502, 3297, 1100, 2487}
Label | A list of textual entries labeling each value. Generally, this series will have as many entries as there were in the 'Value' series. These entries are shared by all the series in the line plot. | {"North", "South", "Central", "East", "West"}
Error (+) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
Error (-) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}

Line plots provide six icons to choose between three plot sub-types each with two different styles.

## Line plot sub-type and style options.

The icon for a line plot of the sub-type with independent, overlapping lines and of the style without point markers.

- The icon for a line plot of the sub-type with independent, overlapping lines and of the style without point markers.

The icon for a line plot of the sub-type with stacked lines and of the style without point markers.

- The icon for a line plot of the sub-type with stacked lines and of the style without point markers.

The icon for a line plot of the sub-type with stacked proportion lines and of the style without point markers.

- The icon for a line plot of the sub-type with stacked proportion lines and of the style without point markers.

The icon for a line plot of the sub-type with overlapping lines and of the style with point markers.

- The icon for a line plot of the sub-type with overlapping lines and of the style with point markers.

The icon for a line plot of the sub-type with stacked lines and of the style with point markers.

- The icon for a line plot of the sub-type with stacked lines and of the style with point markers.

The icon for a line plot of the sub-type with stacked proportion lines and of the style without point markers.

- The icon for a line plot of the sub-type with stacked proportion lines and of the style without point markers.

## Min-Max Plots

Work in Progress

## Pie Plots

Pie plots present the numeric values from a single series of categorical data as slices of a circular area, the angular arc of each slice determined by the proportional magnitude of each value compared to the overall sum of all the values. For example, if the series had values { 1.12, 4.48, 3.36, 1.68, 0.56}, the contribution of each slice to the total would be {0.10, 0.40, 0.330, 0.15, 0.0 5}, since `0.10= 1.12/(1.12+4.48+3.36+1.68+0.56)`, and the angular arcs of the wedges would be {36, 144, 108, 54, 18} degrees, since `36=0.10*360`.

Pie plots do not have any sub-types.

Pie plot styles provide two choices for the rendering of the pie chart, either with all slices linked into one overall circle, or with gaps between the slices. The size of the gap is a property of the pie plot which can be changed.

### An example of a pie plot

A screenshot of a worksheet area showing a data table and a pie plot made with those data.

This screenshot shows a table of data and a pie plot. The data consist of a single data series organized in a row and starting with the word "Widgets". The series has values in five categories. The legend includes the names of the different data categories.

Each pie plot contains a single series which can include three elements although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The legend added to a pie plot identifies the different categories using the entries in the 'Label' element.

## The data in each pie plot series

Element | Type | Example
Name | A single textual entry labeling the data series. | {"Widgets"}
Value | A list of numeric values. | {1293, 2502, 3297, 1100, 2487}
Label | A list of textual entries labeling the category of each value. Generally, this series will have as many entries as there were in the 'Value' list. These will be used in the legend which may be displayed with the pie plot. | {"North", "South", "Central", "East", "West"}

Pie plots do not have any sub-types but provide two icons to distinguish the style of the plot allowing a choice between pie plots which comprise a single circular area or plots with distinct pie slices separated by small gaps.

## Line plot sub-type and style options.

The icon for a pie plot of the style with joint slices.

- The icon for a pie plot of the style with joint slices.

The icon for a pie plot of the style with separated slices.

- The icon for a pie plot of the style with separated slices.

## Polar Plots

Work in Progress

## Radar Plots

Radar plots present the numeric values of categorical data as a set of points plotted along a set of axes radiating from a central point, with as many axes as there are values in the series and with the points connected by a line, possibly with the interior of the shape filled in. Sequential data values are considered to belong to different categories and are plotted on separate axes which are not necessarily orthogonal and radiate from a central point. Sequential points are connected by a line with the final point connected back to the first to form a closed polygon. The data values from different series are assigned to categories based on the position of the value in the series, for example, the second data value taken from each series all share one category and will therefore all be plotted on the same axis. The data values are plotted along the axis of each class according to their numeric value.

Radar plots do not have any sub-types.

Radar plot styles provide three choices for the rendering of the chart. The first style presents the radar chart as only a polygon of lines. The second style also includes a marker where the data values are plotted on each axis. The third style plots the radar chart as a filled polygon.

### An example of radar plots

A screenshot of a worksheet area showing a data table and three radar charts made using those data.

This screenshot shows a table of data and three radar plots. The data consist of three series organized by row and starting with the words "Widgets", "Gadgets", and "Lumpets". Each of these series has values in five categories. The three graphs illustrate the three sub-types of radar plots, with the top left plot including lines only, the top right plot including both lines and markers on the points, and the bottom middle plot using filled polygons.

Each series in radar plots can include three main elements and two error elements, although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The 'Label' element is shared by all of the series. The legend added to a radar plot identifies the different series, by default using the entries of the 'Name' element of each series. The two error elements include a list for errors in the positive direction and one for errors in the negative direction.

## The data in each radar plot series

Element | Type | Example
Name | A single textual element labeling the data series. | {"Widgets"}
Value | A series of numeric values. | {1293, 2502, 3297, 1100, 2487}
Label | A series of textual elements labeling each value. Generally, this series will have as many entries as there were in the 'Value' series. | {"North", "South", "Central", "East", "West"}
Error (+) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
Error (-) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}

Radar plots provide three icons distinguishing the three different styles.

## Radar plot sub-type and style options.

The icon for a radar plot with the style of simple lines only.

- The icon for a radar plot with the style displaying simple lines only.

The icon for a radar plot with the style displaying both lines and point markers on the data values.

- The icon for a radar plot with the style displaying both lines and point markers on the data values.

The icon for a radar plot with the style displaying a filled area.

- The icon for a radar plot with the style displaying a filled area.

## Ring Plots

Ring plots present the numeric values of categorical data as segments of circular rings. Sequential data values are considered to belong to different categories and are plotted with distinct patterns. The data values from different series are assigned to these categories based on the position of the value in the series, for example, the second data value taken from each series all share one category. The data values are used to determine the size of the arc based on the proportionate size of the data value to the sum of all data values in the series. For example, if the series had values { 1.12, 4.48, 3.36, 1.68, 0.56}, the contribution of each ring section to the total would be {0.10, 0.40, 0.330, 0.15, 0.0 5}, since `0.10= 1.12/(1.12+4.48+3.36+1.68+0.56)`, and the angular arcs of the sections would be {36, 144, 108, 54, 18} degrees, since `36=0.10*360`.

Ring plots do not have any sub-types.

Ring plot styles provide two choices. Ring plots can be plotted with all segments linked into a single overall ring, with different series plotted immediately adjacent to one another in sequentially larger rings. Alternatively, the segments of the outermost ring can be split and float a certain distance away from the next ring.

### An example of ring plots

A screenshot of a worksheet area showing a data table and two ring plots made with those data.

This screenshot shows a table of data and two ring plots. The data consist of a single data series organized in a row and starting with the word "Widgets". The data consist of three series organized by row and starting with the words "Widgets", "Gadgets", and "Lumpets". Each of these series has values in five categories. The two graphs illustrate the two sub-types of ring plots, the left most plot without any gaps and the right most plot having the outer plot with gaps.

Each series in ring plots can include three main elements and two error elements, although only the value element is necessary. The series can have a 'Name' element, which is a single text entry used to identify the series, must have a 'Values' element, which is a sequence of numeric values, and may have a 'Label' element, which is a sequence of text entries used to identify the categories. All of these elements can be defined as references to a region of the worksheet, as literally defined entries, or as formula expressions which result in the correct type. The 'Label' element is shared by all of the series. The legend added to a ring plot identifies the different series, by default using the entries of the 'Name' element of each series. The two error elements include a list for errors in the positive direction and one for errors in the negative direction.

## The data in each ring plot series

Element | Type | Example
Name | A single textual element labeling the data series. | {"Widgets"}
Value | A series of numeric values. | {1293, 2502, 3297, 1100, 2487}
Label | A series of textual elements labeling each value. Generally, this series will have as many entries as there were in the "Value" series. | {"North", "South", "Central", "East", "West"}
Error (+) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
Error (-) | A list of numeric values with as many elements as there were in the 'Value' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}

Ring plots provide two icons distinguishing the two different styles.

## Ring plot sub-type and style options.

The icon for a ring plot with the style of displaying series in contiguous rings.

- The icon for a ring plot with the style of displaying series in contiguous rings.

The icon for a ring plot with the style of displaying the outermost series separated from the rest.

- The icon for a ring plot with the style of displaying the outermost series separated from the rest.

## Statistics Plots

Work in Progress

## Surface Plots

Surface plots are used to plot (`x`,`y` ,`z`) points in three-dimensional space as a surface where z is interpreted as the height above the `xy`-plane. A &gnum; chart of course shows the projection of this surface in 3-space onto a 2-dimensional sheet.

Surface plot sub-types provide for 2 distinct ways of providing the data for a surface plot.

The first subtype uses an `n` by 1 or 1 by `n` range for the `x`-values, a second 1 by `m` or `m` by 1 range for the `y`-values and an `m` by `n` range for the `z` values. The plotted points are constructed from these three ranges in such a way that the `z` value in the `i`th column and `j`th row is combined with the `i`th `x` value and the `j`th `y` value. This subtype then uses an `m` by `n` grid for the surface.

### An example of a surface plot with rectangular data area

A screenshot of a worksheet with a data table and a graph containing an surface plot with rectangular data area.

The second subtype uses a direct listing of the `n` points. The `x` values are specified with an `n` by 1 range, so are the `y` and `z` values. The `i`th `z` value is then combined with the `i`th `x` and `i`th `y` value to obtain the points to be plotted.It is not necessary to provide the same number of `y` coordinates for each `x` coordinate or vice versa. &gnum; will interpolate missing values. For this purpose one needs to specify the number of (equidistant) rows and columns to be used for the surface grid. This grid need not align with the provided coordinates.

### An example of a surface plot with x,y, and z series

A screenshot of a worksheet with a data table and a graph containing an surface plot with xyz series.

Surface plots do not have any pre-defined styles.

## The data in each surface plot series with rectangular data area

Element | Type | Example
Name | A single textual element labeling the data series. These will be used in the legend which may be displayed with the surface plot. | {"Widgets"}
X | An optional series of numeric values to be used for the `x` coordinates of the grid. This defaults to {1,2,…,n}. | {1,3,5,6,8,9}
Y | An optional series of numeric values to be used for the `y` coordinates of the grid. This defaults to {1,2,…,n}. | {1,1.5,2,2.5}
Z | A rectangular range of numbers where the number in `j`th row and `i`th column is the height of the `(i,j)` grid point. | A2:J15

## The data in each surface plot series with `xyz` series.

Element | Type | Example
Name | A single textual element labeling the data series. These will be used in the legend which may be displayed with the surface plot. | {"Widgets"}
X | A series of numeric values to be used for the `x` coordinates of the grid. | {1,1.5,2,2.5}
Y | A series of numeric values to be used for the `y` coordinates of the grid. | {1,1.5,2,2.5}
Z | A series of numeric values to be used for the `z` coordinates of the grid. | {1,1.5,2,2.5}

Surface plots provide two icons to choose one of the two surface plot sub-types.

## Surface plot sub-type and style options.

The icon for a surface plot of the sub-type with rectangular data area.

- The icon for an area plot of the sub-type with rectangular data area.

The icon for a surface plot of the sub-type with xyz series.

- The icon for an area plot of the sub-type with xyz series.

## XY Scatterplots

The data values of two series of equal length are plotted on the Cartesian (X-Y) plane, the value from the first series determining the position of the plotted symbol along the X axis, and the value from the second series determining the position of the plotted symbol along the Y axis. Data can be plotted as points only, with each pair of data series having different symbols, or, alternatively, sequential data pairs can be connected by a line, or, finally, both symbols and a connecting line can be used.

### An example of an XY scatterplot

A screenshot of an XY scatterplot and the data used to generate the plot.

This screenshot shows a data table with two different series highlighted which are usable in a scatterplot. Each series is comprised of two lists of numeric values. The screenshot also shows the scatterplot made from these two data series.

Each series in a scatterplot can include three core components and four optional error components. The series may have a name, a single text value which will identify the series in the Graph Guru and in any legend attached to the chart. The series must have two lists of quantitative values, a list of X values and a list of Y values, which must have an equal number of elements. The series may also contain lists of error values for each of the X and Y lists with a positive and a negative component for each.

## The data in each XY scatterplot series

Element | Type | Example
Name | A single textual element labeling the data series. | {"Series1"}
X | A list of numeric values, which will place the values along the horizontal axis. | {14.5, 2.8, 11.8, 5.7, 8.2}
Y | A second list of numeric values, which will place the values along the vertical axis. | {154, 29, 63, 90, 107}
X Error (+) | A list of numeric values with as many elements as there were in the 'X' list. These values can be in the same units as the numeric values in the 'X' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.12, 0.09, 0.11, 0.09}
X Error (-) | A list of numeric values with as many elements as there were in the 'X' list. These values can be in the same units as the numeric values in the 'Value' list, can be proportions or can be proportions multiplied by one hundred. | {0.08, 0.11, 0.10, 0.09, 0.11}
Y Error (+) | A list of numeric values with as many elements as there were in the 'Y' list, and therefore in the 'X' list. These values can be in the same units as the numeric values in the 'Y' list, can be proportions or can be proportions multiplied by one hundred. | {0.09, 0.11, 0.10, 0.12, 0.09}
Y Error (-) | A list of numeric values with as many elements as there were in the 'Y' list, and therefore in the 'X' list. These values can be in the same units as the numeric values in the 'Y' list, can be proportions or can be proportions multiplied by one hundred. | {0.10, 0.09, 0.08, 0.11, 0.11}

XY scatterplots provide three icons to select between different style options. The plots can be rendered with markers at each point, with markers at each point and a line joining adjacent values in the data lists, or with a line but no markers.

## XY scatterplot style options.

The icon for scatter plot of style with only a marker at each point.

- The icon for scatterplot of style with only a marker at each point.

The icon for scatter plot of style with a marker at each point and a line between adjacent points in the value lists.

- The icon for scatterplot of style with a marker at each point and a line between adjacent points in the value lists.

The icon for scatter plot of style with only a line between adjacent points in the value lists.

- The icon for scatterplot of style with only a line between adjacent points in the value lists.

## Configuring Graph Element Properties

Graphs in &gnum; can be configured extensively using the Graph Guru. In this way, the user can determine the data used in the plots, the names and labels associated with the data, the numerical values of the axes and the stylistic presentation of all the graphical elements.

Graphs are configured element by element, first by selecting the element name in the top left area of the second panel of the Graph Guru, shown as area F in fig-graphguru-panels, and, second, by altering the properties in the bottom area of the second panel of the Graph Guru, shown as area J. These changes will be applied to the graph only when the OK button is pressed.

A number of properties of the graph are configured using the &gnum; entry box shown in fig-widget-entryBox.

### The data entry box widget

This screenshot depicts the widget used to enter data as defined values, references or expressions.

The data entry box widget allows users to enter data as defined values (e.g. "A name", 123, or {12,32,14}), as references (e.g. 'Sheet1!A2:B4'), or as expressions (e.g. sin({11,16}) ).

Information can be inserted to the data entry box, first, by selecting the box with a mouse click and, then, either typing data on a keyboard or using the mouse to select a region of the worksheet.

## Background Panels: Graphs & Charts

Several elements of the graph function as background panels for the other elements. These panels can be configured to display a visible background consisting of a solid color, a pattern, a gradient, or an image. Alternatively, the panel can be made transparent to show the underlying panel, if any. Where there are only transparent panels, the worksheet itself will be visible behind the graph.

### The background panel configuration.

This screenshot depicts the two elements of background panels which can be configured, the background fill and the outline.

This screenshot depicts the two elements of background panels which can be configured, the background fill and the outline.

The background panel Fill refers to the area which is behind the entire component. The Outline refers to a solid box which will be drawn around the edge of the component.

The Outline can be configured by selecting a color using the color picker widget and by choosing a size using the spin button box. A size of '-1' indicates that no line will be drawn, whereas sizes zero and above indicate the size of the line that will be drawn.

The Fill can be configured to be a pattern, which includes a solid color, a gradient or an image.

### The pattern background panel fill configuration.

This screenshot depicts the configuration properties for the pattern background panel fill.

This screenshot depicts the configuration properties for the pattern background panel fill.

The fill using a pattern enables the panel background to consist either of a solid color, or of a solid color overlain by a pattern. The top drop down button, labeled Pattern, allows the user to select the pattern overlay from a number of different standard patterns. The pattern in the top left corner is an empty pattern which allows the background color indicated in the third drop down button to fill the panel. The middle drop down button, labeled Foreground, allows the user to select the color of the overlay in the pattern. The bottom drop down button, labeled Background, allows the user to select the color of the underlay. If the pattern is empty, the color of the Background will be the color of the entire panel.

If all of these buttons appear black, change the color of the Background to white to see the pattern and foreground color.

### The gradient background panel fill configuration.

This screenshot depicts the configuration properties for the gradient background panel fill.

This screenshot depicts the configuration properties for the gradient background panel fill.

The background panel can be filled with a gradient transitioning either between two colors or between a color and a tone, either white or black. The top drop down button, labeled Direction, gives the user a number of choices for the direction in which the gradient will operate. The drop down button named Type allows the user to pick between gradients which transition between two colors, the 2 Colors option, and gradients that transition from a color to pure white or pure black, the Brightness option. The drop down buttons for the Start and End colors allow the user to pick the colors in the gradient. For the brightness gradients, a slider allows the user to select the transition direction. Moving the slider toward Brighter will fade the color to white whereas moving the slider toward Darker will fade the color toward black.

If all of these buttons appear black, change the color of the Start button to white to see the gradient.

### The image background panel fill configuration.

This screenshot depicts the configuration properties for the image background panel fill.

This screenshot depicts the configuration properties for the image background panel fill.

The image background fill type allows the user to select an image to fill the background of the panel. The image can be in any file format supported by the `gdk-pixbuf` library as explained in sect-graphics-images. The image can be fit in one of two ways. The image fit can be stretched so the image fills the whole panel area or the image fit can be wallpapered where the image is repeated in a tile pattern to fill up the whole background. The button labeled Select allows the user to call the file selector and choose the file which contains the desired image. On the GNOME desktop, the file chooser has a preview area to see the image before adding it. The size of the image, in pixels, is displayed in the configuration dialog as '# x #' where the number symbol indicates the number of pixels, and the number of pixels in each row comes before the number in each column.

## Titles and Axis Labels

Both Title and Axis Labels can be configured using three tabs. The first tab allows the user to configure the background panel of the title or axis label. The second tab allows the user to select the font that will be used to display the words in the title or axis label. The third tab allows the user to input the actual words which will be used in the graph.

### The font selection for Titles and Axis Labels.

This screenshot depicts the font configuration panel for titles and axis labels in the Graph Guru.

This screenshot depicts the font configuration panel for titles and axis labels in the Graph Guru.

The Style tab allows the user to configure the background panel in the same way this was configured for graphs, charts and grids, as was explained above in sect-graphs-elementProperties-backPanels.

The Font tab is shown in fig-graphics-plots-elementProperties-title-font and consists of three column lists. The first column list allows the user to select the font name by scrolling the list and then clicking on the desired name. The currently selected font name is highlighted in light blue. The second column list allows the user to select the font style including italic and bold styles. The third column list allows the user to select a size for the font. The preview area contains a few characters to illustrate the appearance of the currently selected combination.

The Data tab displays a single entry box in which the user can place the words which will appear in the title or in the label. The user can simply type the text, can add a reference to a section of the worksheet or can add an expression which results in a text value.

## Chart Legends

Chart legends provide a graphical explanation of the data plotted with the names and style of the different series, or categories, plotted in each chart. Legends are configured through two tabs, labeled Style and Font. The Style tab allows for the configuration of the background pane in a manner analogous to the graph, chart and grid background panes, explained in sect-graphs-elementProperties-backPanels. The Font tab allows the configuration of the font that will appear in the legend. This configuration is identical to the configuration of the title and axis label fonts presented in sect-graphs-elementProperties-title.

## Axes

Axes are used in several different kinds of plots to provide quantitative indexes for the scale of each plot direction. &gnum; uses four different kinds of axes. Category axes do not provide a quantitative scale but merely distinguish each different category by providing space for the values of the category along the axis. Continuous axes provide a quantitative measure of each value based on the projection of that value onto the axis. Radial axes are used in radar plots and are continuous axes which radiate from a central point. Circular axes have not yet been implemented.

Line, column and area charts use a category axis to separate the categories along the horizontal direction and a continuous axis to distinguish values in the vertical direction. Bar charts reverse these two axes. XY scatter plots and bubble plots use two continuous axes, one in the horizontal direction, the X-axis, and one in the vertical direction, the Y-axis. Radar plots use three or more continuous axes radiating from a central point. Pie and Ring plots do not use any axes.

### Category Axes

Category axes distinguish the different categories of each value in a category series such as the series in line, bar, column and area plots.

#### Category axis bounds configuration.

This screenshot depicts the 'bounds' tab for the configuration of a category axis.

The Bounds tab allows the user to override the automatic configuration of axis tick marks and labels. Each of the three choices can be over-ridden by deselecting the check box on the left. The check boxes can be deselected by placing the mouse pointer over the check box and clicking with the primary mouse button. When a check box is unselected, the entry box will become active allowing the user to input a different value than the default. The first check box controls the number of tick marks, allowing tick marks to appear after the integer number of categories shown. The second check box controls the number of labels displayed, allowing a regular number of category labels to be skipped. The third check box controls the placement of the orthogonal axis relative to the category axis.

#### Category axis line style configuration.

This screenshot depicts the 'style' tab for the configuration of a category axis.

The Style tab allows the user to configure the line style of the axis, including the color and thickness of the line. The drop down button labeled Color can be clicked to expose the color picker panel which allows the user to select a new color either simply by clicking on an icon or by using the color picker wheel. The size spin button allows a user to change the thickness of the axis by typing a new number in the text box or by clicking on the arrows. A value of '-1' in this box will cause the axis not to be drawn.

The Font tab allows the user to configure the font used to label the separate categories. The font configuration is performed in the same way as the font configuration for titles and axis labels which was explained in sect-graphs-elementProperties-title.

#### The category axis details configuration.

This screenshot depicts the 'details' tab for the configuration of a category axis.

The Details tab allows a user to configure other aspects of the axis.

The Position of the axis is placed in the Low position by default. This can be altered by pressing the radio button in front of the High label which will move the internal button and will alter the position of the axis, moving it either to the top of the graph for horizontal axes, or to the right of the graph for vertical axes.

The Mapping of the axis can be changed simply by clicking on the check box. This will cause a check mark to appear in the box and will invert the axis so that the order of the categories will become reversed.

The Major ticks displayed on the axis can be altered. The labels shown in the plot can be hidden by unchecking the check box in front of the 'Show Labels' text by placing the mouse cursor over the box and clicking with the primary mouse button. The ticks on the axis can be hidden or can be displayed on the outside of the graph, or on the inside of the graph, or on both sides depending on which of the two boxes are checked.

The Minor ticks do not currently have any effect for category axes.

### Continuous Axes: Linear, Radial & Circular

Continuous axes are configured in much the same way as category axes except for some minor differences.

#### Continuous axis bounds configuration.

This screenshot depicts the 'bounds' tab for the configuration of a continuous axis.

The Bounds tab allow users to configure the limits and intervals of a continuous axis. The meaning of the values for Major Ticks and Minor Ticks depends on the type of continuous axes:

Continuous Axes with Linear Scale

- The Major Ticks value gives the distance between major ticks and the Minor Ticks value the distance between minor ticks.

Continuous Axes with Logarithmic Scale

- The Major Ticks value gives the number of decades (powers of 10) between major ticks. The Minor Ticks value gives the number of minor ticks between major ticks.

  If the Major Ticks value is `N`, then the Minor Ticks value can be `0`, `N−1`, or `9N−1`.

The Style tab changes the linear style of the axis in the same way as it acted on category axes. The explanation given in sect-graphs-elementProperties-axes-categorical apply equally well to continuous axes.

The Font tab also allows users to configure the font used in the numeric markers along the axis. Selecting the font for a continuous axis works in the same way as for a category axis as was explained in sect-graphs-elementProperties-axes-categorical.

The Details tab has two small differences compared to category axes. The mapping of the axis can be altered from a linear scale to a logarithmic scale by clicking on the drop down box and dragging to the entry labeled Log. The minor ticks, whose size was configured in the Bounds tab, are displayed for continuous axes unlike for categorical axes.

#### Continuous axis format configuration.

This screenshot depicts the 'format' tab for the configuration of a continuous axis.

The Format tab allow users to configure the numeric type of the elements on a continuous axis. This configuration parallels the configuration of the numeric type of a worksheet cell as explained in number-formatting-overview.

### Grids

Users can add both major and minor grids to an axis. Grids are lines that are perpendicular to the axis at fixed intervals. An example of major (in blue) and minor (in green) grids attached to a vertical axis are shown in fig-graphics-plots-axes-grid.

#### Major and Minor Grids.

This screenshot shows a plot with major (in blue) and minor (in green) grids attached to the vertical axis.

To add either a major or minor grid to an axis, the user selects the appropriate axis in the hierarchy tree of graph components, clicks the Add button below the hierarchy, and selects either MajorGrid or MinorGrid.

When a grid has been added to an axis, it can be selected in the hierarchy tree of graph components and customized in its configuration tab. One can specify the style, color, and thickness (size) of the grid lines as well as specify a fill to be applied to the space between every second pair of consecutive grid lines.

## Plots

Certain of the properties of plots are assigned directly to the plot element and are configured when the plot element itself is selected.

Line plots, Area plots, and XY scatter plots do not have any plot level properties which can be configured.

### Bubble plots

The bubbles in bubble plots are used to represent a third data component with the size of the bubble representing the value of the third component.

#### The configurable properties of a bubble plot.

This screenshot depicts the properties of a bubble plot which can be configured.

The first choice in the bubble plot properties allows the user to represent the bubble value based on the area or the diameter of the bubble. The representation of a bubble using the surface is similar to using a log scale since the area is a squared quantity.

The Show negative values property, if the check box is checked, will cause negatives values to be shown with the size of the bubble based on the absolute value of the value and the style of the bubble having a white fill.

The Vary colors by bubble, if the check box is checked, will cause each value in a series to be displayed with a different fill color instead of coloring all the values in a single series with the same color.

The bubbles in a series are scaled relative to each other with the maximum value having a default, fixed size and the other values being scaled to this maximum bubble. Using this spin button, the default size of the maximum bubble can be altered.

### Pie plots

Pie plots represent the data values as slices of a circular area, with the central angle of each slice, or wedge, proportional to the size of the value compared to the sum of all the values in the series.

#### The configurable properties of a pie plot.

This screenshot depicts the properties of a pie plot which can be configured.

The slices by default are plotted clockwise starting from the vertical which is considered 0 degrees. The first option allows the user to set a different starting point for the pie series by changing the value in the spin box. The value will increase to 360 degrees and then reset to zero.

Pie plots can be displayed with the slices separated from each other which in certain situations may improve the visual clarity of a pie plot. The second spin button allows the slices to be separated.

The colors of each slice, by default, are all different to allow the easy visual distinction between each slice. Since pie plots only allow a single series to be plotted, there is no need to use color to associate the values from different series. By unchecking this box, all of the slices in a pie chart can be made to follow the color scheme defined in the plot series Style tab. However, if this box is unchecked, the outlines of the slices must be styled with a different color for the slices to be distinguishable.

### Bar and Column plots

Bar and column plots can be displayed with different sized gaps between categories and different overlaps between the values of different series in each category.

#### The configurable properties of bar and column plots.

This screenshot depicts the properties of bar and column plots which can be configured.

The Gap describes the separation between the values plotted in each category. By default, the gap between categories is one and half times the width of a bar or a column. This spin button can be used to decrease the gap to zero, so there is no gap between categories, or increase the gap to 500% so the gap is five times the size of a bar or a column.

The Overlap describes the separation between values of the different series in each category. By default these values will be plotted immediately adjacent to each other. This spin button can be lowered to minus 100% which leaves a gap the size of a bar or column between the values of each series. Alternatively, the values can be made to overlap up to 100%, a complete overlap. When values completely overlap, the latter series are plotted on top of the first series and a value may be completely obscured. In this case it may be possible to use partially transparent colors for the different series to allow both values to be visible.

### Radar plots

Radar plots have as many axes as there are categories in each series.

#### The configurable properties of a radar plot.

This screenshot depicts the properties of a radar plot which can be configured.

By default the axis for the first category is vertical leaving the center point in the upward direction. The first spin box in the radar plot properties allows a user to change this orientation. The spin button can increase from zero degrees to 359 degrees when it will reset to 0.

The Vary colors by slice property is probably a mistake which should not be part of radar plot properties.

### Ring plots

Ring plots are similar to pie plots but may have an empty center and can be made with multiple series.

#### The configurable properties of a ring plot.

This screenshot depicts the properties of a ring plot which can be configured.

Like pie plots, ring plots assign values to the slices of a circular area by representing the magnitude of the value by the central angle of the slice, although for ring plots the center of the circular area is empty. Like pie plots, the first slice is plotted starting clockwise from the vertical and this first option can change the beginning point of the first slice's angle.

The slices of a ring plot can also be separated. The Slice Separation option allows a user to determine the proportional size of the gap between slices.

The Center size option determines the size of the hole in the middle of the rings as a fraction of the total radius. The center size can be altered in 5 percent increments.

The Vary colors by slice check box allows the user to assign colors either by slices, which is the default, or by series. To use color to distinguish series rather than categories, this button should not be checked.

## Data Series

Each plot will have one or more 'series' which organize the data values. Each series element has a number of properties. The element will have a Style tab with which the style of the line and point markers, or the area and outline can be set. Each series element will have a Data tab in which the name of the series, the values used for the series and any labels associated with these values can be entered. The data values will generally be entered as references to cells on a worksheet which will allow the plots to be automatically altered when the values in the worksheet change. The series may also have one or more Error tabs in which error values can be associated to the data value of each element in the series.

### Series line style

Series in line plots, in some radar plots and in scatter plots will have a style tab in which the graphical style of the lines and point markers can be established.

#### The configurable properties of a line style.

This screenshot depicts the properties of a line style which can be configured.

The properties of a single value data series include an optional name, a required list of values and an optional list of labels. The name, in this case, is a reference to cell D7 in the first worksheet. The values are the contents of the cells in the range E7:I7. The labels are the contents of the cells in the range E6:I6. Note that there are as many cells in the labels range as in the values range.

The Line properties include the line color and size. The color can be altered in the standard way using the drop down color chooser. The width of the line can be changed with the spin box. A line size of '-1' means that the line will not be plotted.

The Marker properties determine the style of the graphical symbol which will be plotted for each data value. The first drop down box allows the user to choose between a number of different symbols. The blank symbol indicates that no symbol will be plotted where the data value would be. Each shape will have a fill color, and an outline with both a color and a size. The colors can be changed by clicking on the drop down box and picking one of the given colors or using the color picker to select a new color. The size of the outline can be altered by clicking in the text area and editing the value or by using the spin arrows to increase or decrease the size.

### Series filled style

Series in bubble plots, area plots, bar plots, column plots, filled radar plots, and ring plots will have a Style with fill and outline properties. These properties are the same as those presented for background panels in sect-graphs-elementProperties-backPanels and are changed in the same way.

#### The configurable properties of a filled style.

This screenshot depicts the properties of a filled style which can be configured.

The Fill properties will determine the character of the inside of the area. The fill type can be none, pattern, gradient, or image, in the same way as the fill of background panels. If images are used for the background, the whole image will be shown and it will be scaled to the size of the area.

The Outline properties will determine the size of the linear element that surrounds the area. The color and size of this outline element can be altered.

### Series data: single values

The Data tab allows the user to configure the data contents of the series. Some of these data contents are optional, as is indicated by the parentheses around the label. At the minimum one set of numerical quantities will be required.

The entry boxes in the Data tab can be filled in several ways. The data can be a static value or array such as a sting literal, "SeriesName", or a group of values, `{12.05, 73.02, 128.89}`. Note that the separator between elements in the array will depend on the locale since the glyph between whole numbers and decimal fractions differs around the world. Alternatively, the value of an entry box can be the reference to a cell or to a range. This reference can either be typed into the entry box or can be entered by clicking in the entry box text area and then selecting the range on the worksheet. Finally, the value in the entry box can be an expression, such as `sin({120, 982, 140})`.

Single series involve the simplest data. They may have an overall name, must have a list of values, and may have a list of names, with as many names as there are numbers in the values list, which will act as category names. For plot types with more than one single list series, the label names will be shared between all the series.

#### The configurable properties of single value data series.

This screenshot depicts the properties of a single value data series which can be configured.

The Name property is a single string which will give a tag to the series itself. A name is not required. This name will be used in the Graph Guru to name the series and may be used in a chart legend to describe the series.

The Values property must contain a list of numeric quantities. A list of values is required. The values can be described either directly as a static array, described through a reference to a cell range with numeric values, or described through an expression which results in the list of quantities.

The Labels property describes the names of the categories. This property is not required. must be a list of text elements, with as many elements as there are quantities in the list of values. These elements will provide the elements in the legend for pie and ring plots. For line, area, bar and column plots, the labels will provide the category names for the axis with categories.

The Show in Legend property determines if this series will be shown in the legend if a legend is added to the chart. It is sometimes useful to exclude certain series from the legend. If the box is checked, the series will be included in any legend displayed in the chart; if the box is not checked, the series will not be displayed in the legend. The box can be unchecked by placing the mouse pointer over the box and clicking with the primary mouse button.

### Series data: X and Y values

Series with dual data values allow plots to be constructed in which one value is plotted against the other. XY scatter plots require this type of data.

#### The configurable properties of dual value data series.

This screenshot depicts the properties of data series with two values, an x and a y, which can be configured.

Dual data series require two sets of values, an X list and a Y list.

The Name property is a single text element that will name the series in the graph guru and in any legend in the chart.

The X property is a list of quantitative values that will provide the horizontal positioning of each element. This list is required.

The Y property is a list of quantitative values that will provide the vertical positioning of each element. This list is required and must have the same number of elements as the list of X values.

### Series data: bubble values

Bubble series are simple extensions of the XY series to include a third data value, often called W, which will determine the size of the bubble.

#### The configurable properties of bubble data series.

This screenshot depicts the properties of a bubble data series with three values which can be configured.

The Name property is a single text element that will name the series in the graph guru and in any legend in the chart.

The X property is a list of quantitative values that will provide the horizontal positioning of each element. This list is required.

The Y property is a list of quantitative values that will provide the vertical positioning of each element. This list is required and must have the same number of elements as the list of X values.

The Bubble property is a list of quantitative values that will provide the size of the bubbles associated to each element. This list is required and must have the same number of elements as the lists of X and of Y values.

### Series error values

Several plot types allow the plotting of error values using whisker plots. The series in these plot types will have extra tabs allowing the whisker positions to be listed. Line, bar, column and area plots allow an error plot to bracket the plotted quantitative value in the direction of the quantitative axis. XY scatter plots and bubble plots allow whiskers in both directions.

#### The configurable properties of data series error values.

This screenshot depicts the properties of the error values in a data series which can be configured.

The Error Category includes several different categories which can be selected by clicking on the drop down box and dragging the mouse pointer onto the appropriate entry. If the error category is set to "none", no error bars will be plotted. If the category is set to "absolute" the values in the error lists will be considered to be in the same units as the axis. If the category is set to "relative", the values in the error list are assumed to be a fraction of the total of each value. If the category is set to "percent", the values in the error list are assumed to be 1/100 th of the fraction of the total of each value. Note that if the cells in the worksheet are already set to the percent format, they should be incorporated as "relative" errors.

The Style properties alter the appearance of the error whiskers. The Display property can be used to prevent the display of any whiskers, to allow only upper or lower whiskers, or to display both. The Width property alters the width of the outer marker of the whisker. The Line width property alters the size of the whiskers. The color box selects the color of the line used to draw the whiskers.

The Values properties describe the lists of quantitative values which will be used for the whiskers. These lists are required if an error is to be displayed and the lists must have as many elements as were in the list of data "Values". The positive (+) list quantifies either only the upper error values if the lower values are not displayed or the negative list is defined. The positive list can also be used for both error values if the errors are symmetrical. The negative (-) list quantifies the lower whisker.

## Pre-Selecting Data

This section is not yet written.