[SciPy-user] vectorize(function) did not return arrays?

[Yichun Wei]

Dear Experts,

1) I suppose vectorize could return arrays, (I was evaluating a function 
over a 2-d grid, and each function call should return an array at every 
point in this grid as a result. I would like to construct a 3-d array 
with these results.)

def helper(x,y):
	return myconvolve (a[x,y], k[x,y]) [NewAxis,NewAxis,:]
	
vec_helper = vectorize(helper)
x, y  = ogrid[ 0:16, 0:16 ]
lres  = zeros((16,16),'O')
lres  = vec_helper(x,y)

I read through the previous posts on this list by Travis,
http://mail.python.org/pipermail/python-list/1999-June/004440.html
Also I find on Travis's pylab pages:
"There is also a class that allows wrapping an arbitrary Python function 
with scalar inputs or outpus so that the wrapped function behaves like a 
ufunc (taking array arguments and returning array array arguments". Thus 
I supposed this should be a mature feature in Scipy. However I could not 
get results as expected. Did I do anything wrong here.

Also,
2) The code
lres  = zeros((16,16),'O')
lres  = vec_helper(x,y)
does not work either. Long ago (also in 1999), there was someone 
complaining about this:
http://mail.python.org/pipermail/python-list/1999-June/004440.html
But there was no concrete anwser to this. The work-around does not work 
for me. I suppose there should be some better way to do this otherwise 
people won't stop talking about this issue... I dug a little via google 
but it could not tell me more on this...

Do you have any suggestion? Thanks in advance!

- yichun