Re: [Matplotlib-users] Using the same color range for multiple plots

[Eric F. <ef...@ha...>]

cneff wrote:
> Hi guys,
> 
> I've tried to google this and look through the examples but its not quite
> working for me. Say I have two sets of data I want to make contour plots out
> of
> 
> from pylab import *
> 
> x=arange(-3.0,3.0,.025)
> 
> y=arange(-2.0,2.0,.025)
> 
> X,Y = meshgrid(x,y)
> 
> Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
> Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
> 
> Now if I would go
> 
> plt1 = subplot(211)
> contourf(X,Y,Z1)
> colorbar()
> 
> plt2 = subplot(212)
> contourf(X,Y,Z2)
> colorbar()
> 
> we would see that the same colors correspond to different numerical values,
> because the ranges of Z1 and Z2 are different.  I want it to be defined on
> the same range, so that red on plt1 corresponds to the same numerical Z
> value as red on plt2.  How do I go about doing that?

Instead of relying on autoscaling to set the color levels, set them 
explicitly to the same set of values in both calls to contourf by adding 
a fourth argument.

e.g.

levs = arange(0,1.01,0.1)

...

contourf(X, Y, Z1, levs)

...

contourf(X, Y, Z2, levs)

...

Eric