On Sun, 1 Nov 2009, Alan G Isaac wrote: > 1. I'm having a some trouble replicating this problem on a > recent gnuplot download, and I'm wondering if the gretl version > of gnuplot (for Windows) compiles in support for pngcairo and if > that takes over as the PNG backend for the gretl version? (If I > use a downloaded gretl, the PNG back end does not give me the > problem, but if I change pngcairo to png I still get the problem > with gretl.)
This can get a bit confusing. Historically, there are two back-ends for producing PNG in gnuplot (maybe 3 if you go back far enough?). One uses the libgd graphics library, and one (a newer addition) uses the pango and cairo libraries. The wgnuplot.exe that ships with gretl uses the cairo-based PNG writer exclusively. (It does not support libgd, which is a mess code-wise and has poor support for font selection.) If you have a build of gnuplot that includes libgd support then the gnuplot command "set term png" uses the libgd-based writer, and "set term pngcairo" uses the cairo-based one, if available. If libgd support is not present but cairo support is, then both "set term png" and "set term pngcairo" have the same effect: use the cairo driver. > 2. Just out of curiosity, how did you get the help to work in > gretl's gnuplot (I'm on Vista), and is that something you could > give back to gnuplot? Hmm, I wasn't aware of doing anything special. I just built the help using the tools in the gnuplot source tree (slightly adapted for a cross-build on Linux), plus Microsoft's hcw.exe (running under wine) to compile the final .hlp file. Allin
