4. Basic plotting with Python

Basic plotting with Python

This screencast shows how to load a data file and then plot one column versus the other. For the numpy.loadtxt command to work as shown, the data should be arranged in columns (separated by space, tabs or commas) and  should comprise of floating point numbers or integers. Any headers or footers should be preceeded by a hash (‘#’).

I should have mentioned this in the last tutorial –  please do not hesitate to contact me via comments regarding problems and queries.


UPDATE: Those of you on non-Mac operating systems should be aware of one thing. I didn’t realise this but when I execute a plot command in the Ipython shell on a mac, the plot shows up immediately. On Linux and Windows, you need to execute pylab.show() after the plot command for the first plot in the session. Users can bypass this weirdness and the annoyance of always typing in pylab. or numpy. before the commands by starting Ipython in the pylab mode. This is done by typing ipython -pylab instead of plain ole ipython in your terminal.

Post contributed by Shrividya Ravi, VUW

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