title: script for creating images from data files in gnuplot
body: <p>I have several data files named sequentially as '1.dat', '2.dat' ..., '100.dat'.
  I want to create a png(or any other type) image for each of these data file in Gnuplot.
  My ultimate motif is to create a movie from the images thus generated but I found packages available for that confusing and would prefer to do it step by step.
  How can I write script for creating images out of the data files? Thanks.</p>