I believe that the current version 1.159 of plot2d is over-riding/ignoring
any gnuplot settings that are passed via gnuplot_preamble.
E.g.
(%i1) gpp : "set ylabel \"x\"; set terminal latex; set output \"sin.tex\";";
(%o1) set ylabel "x"; set terminal latex; set output "sin.tex";
(%i2) plot2d(sin(x),[x,0,2*%pi],[gnuplot_preamble,gpp]);
produces a graph on the default terminal, with the ylabel set to its
default value.
Leo
--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.