numarray.array can be VERY slow

[Edward C. Jones]

#! /usr/bin/env python

"""Should this program take 4.3 seconds to run? I have a Linux PC with
an AMD Athlon XP 2000+ chip (1.7Gh). I use Python 2.4.1 and numarray
1.2.3, both compliled from source."""

import time, numarray
from numarray.numeri ctypes import *

nested = []
for i in range(8):
inner = []
for j in range(8):
inner.append(nu marray.ones((25 6,256), Float64))
nested.append(i nner)
t = time.clock()
arr = numarray.array( nested)
print time.clock() - t

[ChinStrap]

Re: numarray.array can be VERY slow

Yes because that is a bad way to things. There is no reason to be
working with a list when it could be done directly with numarray.

[Steven Bethard]

Re: numarray.array can be VERY slow

Edward C. Jones wrote:[color=blue]
> #! /usr/bin/env python
>
> """Should this program take 4.3 seconds to run? I have a Linux PC with
> an AMD Athlon XP 2000+ chip (1.7Gh). I use Python 2.4.1 and numarray
> 1.2.3, both compliled from source."""
>
> import time, numarray
> from numarray.numeri ctypes import *
>
> nested = []
> for i in range(8):
> inner = []
> for j in range(8):
> inner.append(nu marray.ones((25 6,256), Float64))
> nested.append(i nner)
> t = time.clock()
> arr = numarray.array( nested)
> print time.clock() - t[/color]

As mentioned, this has nothing to do with numarray, and everything to do
with your inexplicable use of lists. Why don't you just write this as:

arr = numarray.ones(( 8, 8, 256, 256), Float64)

??

STeVe