assigning to matrix elements in NumPy
fperez528 at yahoo.com
Wed Mar 12 06:23:06 CET 2003
Blair Hall wrote:
> I have just upgraded from NumPy 21 to NumPy 23 and was
> surprised to find that my matrix assignment doesn't work like it
> used to.
> For example:
>>>> from Matrix import *
>>>> m = Matrix( [[1,2],[3,4]])
>>>> m[1,1] = 2
> Traceback (most recent call last):
> File "<interactive input>", line 1, in ?
> File "C:\PYTHON22\lib\site-packages\Numeric\Matrix.py", line 183, in
> value = value[0,0]
> IndexError: invalid index
> Apparently, I should have written
>>>> m[1,1] = Matrix( 2 )
> Is this really indended, or am I confused?
Just to provide you with a reference point, the above code produces the same
error under Numpy 22.0. Now, I've never used the Matrix class, only
regular arrays, so I can't say what the rationale is. But that behavior
definitely looks most bizarre and counter-intuitive to me.
You should ask in the numpy mailing list.
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