Steven Bethard wrote:
> 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)
The code I posted was simplified from a larger program which I have now revised. But I still ask: why did it take 4.3 seconds to run?
Because lists of lists of arrays are difficult to work with.
Lists of arrays are relatively easy to work with: numarray checks to see if all the items are compatible arrays. If they are, then the arrays are all concatenated and you have your final array fairly quickly.
List of lists of arrays are more problematic. Currently, the code doesn't check that that the objects it sees are arrays, so it interprets the arrays as sequences of sequences, and uses the PySequence_* protocol. So you might as well have used list of lists of lists of lists.
See the function setArrayFromSequence in libnumarraymodule.c . If you wish to fix this behavior, I'm sure that a patch would be welcomed. Further questions should probably go to the numarray mailing list.
-- Robert Kern [EMAIL PROTECTED]
"In the fields of hell where the grass grows high Are the graves of dreams allowed to die." -- Richard Harter
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