gnuplotで図を並べる

http://dsl4.eee.u-ryukyu.ac.jp/DOCS/gnuplot/node112.html
multiplotを使う．

#----------
set term postscript color eps
set out 'test.eps'

#----------
set multiplot
set size 0.5

set origin 0, 0.5
pl 'test1.dat'

set origin 0.5, 0.5
pl 'test2.dat'

set origin 0, 0
pl 'test3.dat'

set origin 0.5, 0
pl 'test4.dat'

#----------
set nomultiplot

#----------
set out
set term win