Table of values and graph : tablefunc and plotfunc

### 2.17.4 Table of values and graph : `tablefunc` and `plotfunc`

`tablefunc` is a special command that should be run from inside the spreadsheet. It returns the evaluation of an expression ex depending on a variable x for x=x0, x0+h,.... :

`tablefunc(ex,x,x_0,h)` or `tablefunc(ex,x)`

In the latter case, the default value for `x``0` is the default minimum value of x from the graphic configuration and the default value for the step h is 0.1 times the difference between the default maximum and minimum values of x (from the graphic configuration).
Example: type `Alt+t` to open a spreadsheet if none are open. Then select a cell of the spreadsheet (for example `C0`) and to get the table of `"sinus"`, input in the command line of the spreadsheet :

`tablefunc(sin(x),x)`

This will fill two columns with the numeric value of `x` and `sin(x)` :

- in the first column the variable `x`, the value of the step `h` (1.0), the minimum value of x (-5.0), then a formula, for example `=C2+C$1`, and the remaining rows of the column is filled by pasting this formula.
- in the next column the function `sin(x)`, the word "Tablefunc", a formula, for example `=evalf(subst(D$0,C$0,C2))`, and the remaining rows of the column are filled by pasting this formula.

Hence the values of `sin(x)` are on the same rows as the values of `x`. Note that the step and begin value and the expression may be easily changed by modifying the correspondant cell.

The graphic representation may be plotted with the `plotfunc` command (see 3.2.1).