gnuplot_plot_ctrl — Plot control values using gnuplot.
gnuplot_plot_ctrl is obsolete and is only provided for
reasons of backward compatibility.
gnuplot_plot_ctrl displays a tuple of control values
using gnuplot. If there is an active gnuplot sub-process (started
gnuplot_open_pipe), the image is displayed in a
gnuplot window. Otherwise, the image is output to a file, which can
be later read by gnuplot. In both cases the gnuplot output stream
is identified by
Identifier for the gnuplot output stream.
→(real / integer)
Control values to be plotted (y-values).
gnuplot_plot_ctrl returns the value if
GnuplotFileID is a valid gnuplot output stream, if the
data file for the current plot could be opened, and if only integer
or floating point values were passed. Otherwise, an exception is