Close all open gnuplot files or terminate an active gnuplot sub-process.
gnuplot_close closes all gnuplot files opened by gnuplot_open_file or terminates the gnuplot sub-process created with gnuplot_open_pipe. In the latter case, all temporary files used to display images and control values are deleted. This means that gnuplot_close must be called after such a plot sequence.
gnuplot_close always returns the value TRUE.
gnuplot_open_pipe, gnuplot_open_file, gnuplot_plot
gnuplot_open_pipe, gnuplot_open_file, gnuplot_plot