Re: [Matplotlib-users] function domain problems

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

I suggest using masked arrays to ensure you are only trying to plot real 
numbers:

def f(x):
     y = log(x)
     ygood = (y < 1e38) & (y > -1e-38)
     yy = nx.ma.masked_where(ygood == 0, y)
     return yy

Note the parentheses and peculiar use of bitwise-and in the definition 
of ygood.  This is a hack to get around the fact that the logical-and 
operator in python cannot be overloaded at present, and so is not 
available in numpy.

Eric

Davidlohr Bueso A. wrote:
> Hi all,
> 
> I'm having trouble plotting functions were the domain aren't the real
> numbers (R). Functions like x**-n, log(x), etc. Does anyone know if
> there's a simple way of solving this problem. Here's a little script and
> it's error:
> 
> from pylab import *
> 
> def f(x):
>         return log(x)
> 
> x = arange(-3, 4)
> plot(x, f(x))
> show()