[Numpy-discussion] how to get an array with "varying" poisson distribution

Robert Kern robert.kern at gmail.com
Mon Jul 24 16:20:42 CDT 2006


Sebastian Haase wrote:
> Hi,
> Essentially I'm looking  for the equivalent of what was in numarray:
>     from numarray import random_array
>     random_array.poisson(arr)
> 
> That is: if for example arr is a 256x256 array of positive integers, then this 
> returns a new array of random numbers than are drawn according to the poisson 
> statistics  where arr's value at coordinate y,x  determines the mean of the 
> poisson distribution used  to generate  a new value for y,x. 

I'm afraid that at this point in time, the distributions only accept scalar 
values for the parameters. I've thought about reimplementing the distribution 
functions as ufuncs, but that's a hefty chunk of work that won't happen for 1.0.

I'm afraid that, for now, you're stuck with iterating over the values.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
  that is made terrible by our own mad attempt to interpret it as though it had
  an underlying truth."
   -- Umberto Eco





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