Re: [Matplotlib-users] Speeding up pcolor plot

[Paul I. <piv...@gm...>]

Hey again, Brad,

Brad Malone, on 2011-12-19 23:44,  wrote:
> Hi, I am plotting a grid with pcolor. Below I've got a 1000x1000 grid.
> 
> xi=linspace(-0.1,x[-1]+2,1000)
> > yi=linspace(-0.1,maxfreq+10,1000)
> > print 'Calling griddata...'
> > zi=griddata(x,y,z,xi,yi,interp='nn')
> > plt.pcolor(xi,yi,zi,cmap=plt.cm.hot)
... 
> How could I modify my above data (which is in xi,yi,and zi) to
> work with imshow (which seems to take 1 argument for data).

Try either:

  plt.matshow(zi,cmap=plt.cm.hot)

or

  plt.imshow(zi,cmap=plt.cm.hot)

The first should be the quickest - it doesn't do any
fancy interpolation, and actually just passes some arguments to
the second. Using imshow directly, however, allows you to set a
different type of interpolation, should you desire it. If
you want xi and yi to be accurately reflect in the plot, you
might have to play around with changing the axis formatters
(though there might be an easier way of doing that, which escapes
me right now)

best,
-- 
Paul Ivanov
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