GNUPlot 001: Postscript postproduction

I generated a graph with gnuplot:
Settings were:

 set terminal postscript
 set output 'outfile.ps'
 set size 0.6,0.6
 set xlabel "Reaction Coordinate"
 set ylabel "dE[kcal/mol]"
 plot 'data.dat' with lines lw 4
 set output

If i open this file in preview, the file is oriented 90° counter-clock wise. This can be fixed with 'ps2eps'.
The command I used was:

ps2eps -f -R + -B -l data.eps