#!/usr/bin/env python3
# ----------------------------------------------------------------
# Programmer(s): Daniel R. Reynolds @ SMU
# ----------------------------------------------------------------
# SUNDIALS Copyright Start
# Copyright (c) 2002-2025, Lawrence Livermore National Security
# and Southern Methodist University.
# All rights reserved.
#
# See the top-level LICENSE and NOTICE files for details.
#
# SPDX-License-Identifier: BSD-3-Clause
# SUNDIALS Copyright End
# ----------------------------------------------------------------
# matplotlib-based plotting script for heat1D.c example

# imports
import sys
import pylab as plt
import numpy as np

# load mesh data file
mesh = np.loadtxt("heat_mesh.txt", dtype=np.double)

# load solution data file
data = np.loadtxt("heat1D.txt", dtype=np.double)

# determine number of time steps, mesh size
nt, nx = np.shape(data)

# determine maximum temperature
maxtemp = 1.1 * data.max()

# generate plots of results
for tstep in range(nt):

    # set string constants for output plots, current time, mesh size
    pname = "heat1d." + repr(tstep).zfill(3) + ".png"
    tstr = repr(tstep)
    nxstr = repr(nx)

    # plot current solution and save to disk
    plt.figure(1)
    plt.plot(mesh, data[tstep, :])
    plt.xlabel("x")
    plt.ylabel("solution")
    plt.title("u(x) at output " + tstr + ", mesh = " + nxstr)
    plt.axis((0.0, 1.0, 0.0, maxtemp))
    plt.grid()
    plt.savefig(pname)
    plt.close()


##### end of script #####
