set output 'four_cold_histograms.ps' set term postscript color 'Helvetica' 18 set grid set key top right set xlabel 'Counts in a pixel' set ylabel 'Number of pixels ' set title 'Histograms of cold dark frames, Sep 24, 2003 ' plot [50:300][] 'dark1cold-001d.his' index 0 using 1:2 lc 1 pt 1 ps 1 lw 4 t '1 sec' , 'dark10cold-001d.his' index 0 using 1:2 lc 3 pt 1 ps 1 lw 4 t '10 sec' , 'dark20cold-001d.his' index 0 using 1:2 lc 4 pt 1 ps 1 lw 4 t '20 sec' , 'dark30cold-001d.his' index 0 using 1:2 lc -1 pt 1 ps 1 lw 4 t '30 sec' set output quit