Q:

gnuplot and "Failed to initialize wxWidgets"

i want to plot120 files with gnuplot.
plot '18205.plot' u 1:3 w l t '18205' , '18208.plot' u 1:3 w l t '18208'
Failed to initialize wxWidgets.
         warning: Warning - difficulty fitting plot titles into key
         warning: Too many axis ticks requested (>1e+01)
         warning: Too many axis ticks requested (>1e+01)
         warning: Too many axis ticks requested (>6)

the files looking like
21      4       0.865671
22      4       0.894175
23      4       0.921895
24      4       0.949053
25      4       0.975792
26      4       1.00147
27      4       1.02577
28      4       1.05008

A:

Apparently this is it failing to detect a terminal it likes.  On my Debian stable "gnuplot 4.4 patchlevel 0" I get an identical error until I add some:
set terminal png
...at which point it works fine.  Raaage!

A:

The important bit is this:
Failed to initialize wxWidgets.

This means that gnuplot couldn't open a window to plot using wxWidgets.
Be sure that the terminal where you are running gnuplot can open windows in X. You can do that by typing echo $DISPLAY in the terminal (or !echo $DISPLAY from within gnuplot) and checking if it's not empty and if it makes sense (usually this means a value of :0.0. If it should be anything different, you should know that because you have set it up that way ;) ).
Setting the right X permissions is also necessary if you are running gnuplot as a different user (or on a different host e.g. via ssh) than the one running the graphic environment. in a secure environment xhost + would do, but if you are on a network and specially not behind a firewall, xhost server-running-gnuplot.domain would be a much wiser choice.

A:

I was getting the same errors.  However, I realised that I did not have X permissions in my current terminal window.  This would explain why switching terminal formats to non-X (ie. jpg/png) worked for the guys above as well.

