Getting variables from gnuplot

Sometimes it is useful to get variables from a gnuplot session steered from python, e.g. to extract parameters from a fit. GnuplotBiDir.py is a test of bidirectional interfacing with gnuplot. For this you need a really recent gnuplot (from CVS) . The basic usage is

    from GnuplotBiDir import Gnuplot
    gp=Gnuplot()
    gp("a=10")
    print "var=",gp.getvar("a")

Remark: for an excellent python interface to gnuplot see gnuplot-py and the interactive add-ons to this from IPython.

Mouse clicks

It is now possible (thanks Ethan!) using the pause mouse command to get the coordinates of a mouse-click from python, e.g.

    from GnuplotBiDir import Gnuplot
    gp=Gnuplot()
    gp("set mouse")       # activate mouse 
    gp("plot sin(x)")
    print "Now get coordinates of a mouse-click:"
    gp("pause mouse 'click with mouse' ")
    mouse_x=gp.getvar("MOUSE_X")
    mouse_y=gp.getvar("MOUSE_Y")
    print mouse_x,mouse_y

This works both interactively, but (more interestingly) also from a normal python program! For further details see the test in GnuplotBiDir.py.