After using the command:
gmx sham -f PCAplot2d.xvg -notime -ls gibbs1-2.xpm
(where PCAplot2d.xvg is the PCA plot generated with the gmx anaeig command)
I get the matrix file in a 2D plot, which can be improved by transforming it into an *eps file, using the command:
gmx xpm2ps -f gibbs1-2.xpm -o plot.eps -rainbow blue
How can I obtain 3D free energy landscape after this ?