Passing data array to gnuplot via a pipe in c rather than a file

Question

Right now I am passing a file to gnuplot via a a pipe in c, something like this:

 fprintf(gnuplotPipe, "plot \"data-file.dat\" using 1:2\n"); 

Is there any way that I don't have to write the data to a file and then pass it to gnuplot, so for example somehow pass an array or a stream to gnuplot, so I can skip the writing to a file process and then deleting the file? Any help would be appreciated.

Answer 1

Sure you can do that. An example of a terminal command that plots two points connected by a line is:

echo "plot \"< echo -e '4 5\n 3 2'\" w lp pt 2" | gnuplot

If you want to have postscript output you can add the following:

echo "set terminal postscript; plot \"< echo -e '4 5\n 3 2'\" w lp pt 2" | gnuplot &> out.ps

If you now use system() or popen() (to catch the output stream) the rest should be straightforward.

Edit: There seems to exist some C(++) - Gnuplot interfaces. Check out this website which gives a great overview over C, C++, Python and Fortran wrappers. I'm not sure whether they are up to date and work with the latest Gnuplot versions but if not adapting shouldn't be that difficult.