Digitizing DataΒΆ

During the course of your research, you will inevitably need to compare either with previously published calculations or experiment. Therefore, you will need to digitize data. There is a free, open source program called g3data that works very nicely. You can install g3data on Ubuntu using apt. The basic recipe for using g3data is:

  1. Screen grab a plot from some digital resource and save as a raster image you like (png, jpeg, etc).
  2. Open the image using g3data.
  3. Calibrate g3data by specifying two vertical and two horizontal reference points.
  4. Now you can click on the image and it will store this point. Do this for all data points.
  5. All stored points can then be output to a file or to standard out.

While there is an automatic mode on g3data, and other similar programs, my experience is that it rarely works well enough. If this digitized data is to be used in a publication, it must be precise, and is best done by hand.