Two ways:

• Open a terminal:
  1. Enter 'cplot' followed by the filename in which you wish to open. Note: Be in the directory of the file.

or

• Open a terminal:
  1. Enter 'cplot', and hit enter.
  2. Click on Browse on the graphical interface that shows up.
  3. Enter the directory of the file that you want to bring up in cplot.
  4. Double click on the directory and then click on the file that you want.
  5. Click 'ok', 'open file'.