string_pde, a C code which sets up and solves the partial differential equations (PDE) describing a vibrating string, creating files that can be displayed by gnuplot().
The information on this web page is distributed under the MIT license.
string_pde is available in a C version and a C++ version and a Fortran90 version and a MATLAB version.
fd1d_wave, a C code which applies the finite difference method to solve a version of the wave equation in one spatial dimension.
gnuplot_test, C codes which illustrate how a program can write data and command files so that gnuplot() can create plots of the program results.