Updated 2021-05-17

Run PLplot on the Cluster


  • PLplot is a library of subroutines that are often used to make scientific plots in compiled languages such as C, C++, D, Fortran, Ada, OCaml and Java. PLplot can also be used interactively by interpreted languages such as Octave, Python, Perl and Tcl.
  • This guide will cover how to run PLplot on the Cluster and display the generated plot.
  • You can find PLplot's homepage here.
  • You can see examples in all the different languages PLplot supports here.


  • In this guide we will run PLplot in python as an example. Using an interpreted language allows us to run PLplot interactively, but for the purposes of this guide, we will generate a 2D line plot with no interactive elements.
  • Since PLplot is a graphical application, we will need to run it either a VNC session or through an X11 server. Please refer to the VNC guide or X11 guide for more information.

Walkthrough: Run PLplot on the Cluster

  • This walkthrough will use Python and PLplot to generate a 2D line plot that will be viewed through VNC.
  • The code used in this example comes from PLplot's GitHub repo.
  • plplotTest.py can be found here
  • plplotTestViewer.py can be found here
  • You can transfer the file to your account on the cluster to follow along. The file transfer guide may be helpful.

Part 1: Set up VNC Session

  • Please see the VNC guide for instructions on how to set up the Interactive VNC session

Part 2: Load and Start PLplot on VNC

  • Open terminal in the VNC window by clicking top left Applications > System Tools > scroll down to terminal
  • All commands here on will be typed in terminal in VNC.
  • You will need to load the PLplot module and the Python 2.7 module.
  • You can find which versions are available for any module with module avail [software].
  • Run the following commands to load the necessary modules:
    • module load python/2.7
    • module load plplot/5.9.9
  • Navigate to the directory containing the plplotTest.py and plplotTestViewer.py files which create and display the graph, respectively.
  • View the graph with python plplotTestViewer.py.
  • You will be prompted with the following:

Plotting Options:
 < 1> xwin       X-Window (Xlib)
 < 2> tk         Tcl/TK Window
 < 3> ps         PostScript File (monochrome)
 < 4> psc        PostScript File (color)
 < 5> xfig       Fig file
 < 6> null       Null device
 < 7> tkwin      New tk driver
 < 8> mem        User-supplied memory device
 < 9> svg        Scalable Vector Graphics (SVG 1.1)
 <10> bmpqt      Qt Windows bitmap driver
 <11> jpgqt      Qt jpg driver
 <12> pngqt      Qt png driver
 <13> ppmqt      Qt ppm driver
 <14> tiffqt     Qt tiff driver
 <15> svgqt      Qt SVG driver
 <16> qtwidget   Qt Widget
 <17> epsqt      Qt EPS driver
 <18> pdfqt      Qt PDF driver
 <19> extqt      External Qt driver
 <20> memqt      Memory Qt driver
 <21> xcairo     Cairo X Windows Driver
 <22> pdfcairo   Cairo PDF Driver
 <23> pscairo    Cairo PS Driver
 <24> svgcairo   Cairo SVG Driver
 <25> pngcairo   Cairo PNG Driver
 <26> memcairo   Cairo Memory Driver
 <27> extcairo   Cairo External Context Driver

Enter device number or keyword:
  • Enter 1
  • You should see a display that looks like the following:


  • Congratulations! You successfully ran PLplot on the cluster.