Tutorial - Users 2 - Plotting

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Madagascar also has a robust package of tools for plotting the results of your computations in multi-dimensions! These plots are created using a vector plotting library originally developed by Joe Dellinger at SEP called VPLOT. VPLOT provides a method for making plots that are small in size, aesthetically pleasing, and easily compatible with Latex for rapid creation of production quality images.

VPLOT file format

The VPLOT file format (.vpl suffix) is a self-contained binary data format that describes how to draw the plot on the screen using an interpreter. Since VPLOT is not a standard imaging format, VPLOT files must be viewed with third-party interpreters which we call pens. Each pen interfaces VPLOT with a third-party graphing library such as X11, plplot, opengl, and others. This flexibility makes VPLOT files almost as portable as standard image formats such as: jpeg, png, and gif. Unlike rasterized formats, VPLOT files can be scaled to any size without losing image quality. This feature alone makes VPLOT worth the work, because you don't have to regenerate your images each time you want to change their size!

Plotting programs

To generate VPLOT files, we need to pass our computed RSF files through vplot filters, that convert RSF files to VPLOT files. The vplot filters are named by the type of plot that they produce. The full list of available vplot filters is:

  • sfgraph -
  • sfgrey
  • sfgrey3
  • sfbyte
  • sfbox
  • sfcontour
  • sfcontour3
  • sfcubeplot

<bash> sfgrey < junk.rsf > junk.vpl </bash>