MATLAB2Python

[John Hunter]

>>>>> "Nick" == Nick Carter <nick.carter at roke.co.uk> writes:

    Nick> Also look at Matplotlib for Matlab-like plotting:
    Nick> http://matplotlib.sourceforge.net/

I find python + numeric/numarray + MLAb + scipy + matplotlib to be a
very workable replacement for matlab, but I'm biased :-)

Actually, I used to work all the time in matlab and wrote some fairly
complex applications in it.  I just sort of hit the wall at some point
when I was trying to do networking, dbases, complex data structures,
and so on, in matlab.  You *can* do it with the matlab + the built-in
JVM, but it's not easy, pretty, or fast.

At some point I found myself doing all my work in python and dumping
the results to data files for plotting in matlab.    Since that is a
frustrating solution, I bit the bullet and wrote matplotlib, with the
goal of making plots that look as good as matlab's, and were as easy
to create.

Here is a little comparison of a script to generate some white noise,
convolve it with a low pass filter, and make two plots, one of the
time series and one of the power spectrum.

First in matlab

    dt = 0.01;
    t = [0:dt:10];
    nse = randn(size(t));
    r = exp(-t/0.05);
    cnse = conv(nse, r)*dt;
    cnse = cnse(1:length(t));
    s = 0.1*sin(2*pi*t) + cnse;

    figure(1)
    plot(t,s)

    figure(2)
    psd(s, 512, 1/dt)

And then in matplotlib with a little help from numeric and friends

    from matplotlib.matlab import *

    dt = 0.01
    t = arange(0,10,dt)
    nse = randn(len(t))
    r = exp(-t/0.05)

    cnse = convolve(nse, r, mode=2)*dt
    cnse = cnse[:len(t)]
    s = 0.1*sin(2*pi*t) + cnse

    figure(1)
    plot(t,s)

    figure(2)
    psd(s, 512, 1/dt)

    show()

Cheers,
John Hunter