I have attached here with the .ps file that has heatmap data in it. Is there anyway I can extract the data from the file. I tried with Inkscape, but it is not opening in Inkscape.
Depending on what you mean by extracting. You can open this .ps file in many graphical programs, like photoshop (commercial) or ghostscript (https://www.ghostscript.com, free) and save in any other graphical format, like .jpg or .pdf. This, however, will still be a graphical file.
Thanks Bartosz, but unfortunately it is simply a plain plot with no information on both axes which makes it terribly hard for me to either interpret or explain.