Plot comparison

Visual comparison of plot files from http://tech-chat.de/compare_plot_demos/. You can find the scripts which are used to create these plots in the default branch in scripts/testfun/private.

Here is the generated fltk/dump.m as example.

needs some work

• gnuplot + fltk area_01_1: draws a green background, Matlab a red one. The FLTK plot furthermore shows tiny vertical white stripes.

• gnuplot + fltk colorbar_23_1: xtick unreadable. It should check the text_extent and reduce xticks if the xlabels would overlap.

• gnuplot + ftlk: fill_01_1, fill_02_1: hidden edges keep visible in ML, not with fltk or gnuplot. This seems to be a ML bug when printing to PNG or JPEG and works (same output like gnuplot+fltk) when printing to ps. In FLTK the on-screen images shows the hidden edge and becomes invisible when printing.

• gnuplot + fltk: hold_07_1: red rectangle hides the '^' plot markers. In ML they disappear on-screen as soon as xlim is changed or zoomed. Is this a ML bug? What is the prefered behaviour?

• gnuplot + fltk patch_04_1: the demo incorrectly assumes the patch "facecolor" is "flat" as octave currently sets this by default (whereas in matlab "facecolor" is "none" by default). This should be fixed with bug#42159 (this probably is also the cause for black faces in shrinkfaces*)

• gnuplot + fltk shrinkfaces_04_1: shows "inverted?/outer faces", completly different from matlab

• fltk text_03_01: can't print multi-line text objects bug#31468

gnuplot only differences

There are a lot of gnuplot differences and it might be nice to fix those, but someone would have to take an interest. Octave is moving towards OpenGL for all plotting so most developers focuses on bug fixes for that toolkit.

Nevertheless here are some visual gnuplot ONLY problems which need some attention:

• gnuplot fill_03_1: unusable

• gnuplot ezsurf_02_1: distorted despite "axis equal"

• gnuplot isosurface_01_1: wrong scale, edges missing

• gnuplot trimesh_01_1: invisible lines bug#42561. fltk plot is fine.

work in progress

• plotyy_03: chunky dashed line for the '--' linestyle: Thread on ML

fixed

• colorbar ticks: http://hg.savannah.gnu.org/hgweb/octave/rev/04a00ba54557

• gnuplot + fltk compass_01_1: no proper scaling/zoom: A changeset from Stefan Mahr fixing a different part of polar() also solves the auto-scaling issue with compass(). See http://hg.savannah.gnu.org/hgweb/octave/rev/cff49c82f722.

won't fix or Octave only feature

• gnuplot/ML axis_09, axis_10, axis_11, axis_12, axis_13: No, [x,y]axislocation' 'zero' (http://savannah.gnu.org/bugs/?40588). This is an Octave (and gnuplot) only feature. We can either blacklist, or visually skip over the comparison since it is blank for Matlab. Perhaps should be removed from demos or blacklist axis_09 in dump.m script

• matlab comet3_01_1, comet_01_1.png: Only the beginning of the animation is printed. Matlab implements comet in a completely different way which means printing isn't really possible for them.