Plotting streaming data in real-time with Gnuplot

Our friend Thanassis Tsiodras, who you may remember as the creator of the offline Wikipedia reader, wrote in to tell us about a handy way to plot real-time data using standard unix tools.

For the last couple of years, I’ve been working on European Space Agency (ESA) projects – writing rather complex code generators. In the ESA project I am currently working on, I am also the technical lead; and I recently faced the need to provide real-time plotting of streaming data. Being a firm believer in open-source, after a little Googling I found Gnuplot; and quickly hacked a Perl script that spawns instances of Gnuplot and plots streaming data in real-time. Googling doesn’t reveal anything similar, so I published it here.

You can easily pipe any data stream into his druveGnuPlots.pl script, choose the zoom and y-range and it will take care of reading in the data and passing it to Gnuplot with your specifications. This is pretty neat, since it means you can easily plot just about anything and all you need to do is get your measurements into a newline-delimited output format.

Visualize real-time data streams with Gnuplot