[Numpy-discussion] Bug or feature ?

Jean-Luc Menut jeanluc.menut at free.fr
Mon Jan 24 04:49:07 CST 2005


Hello,

I'm using numarray, I'm wondering about the behaviour of some functions 
which seem odd to me:

1) When I want to sum all the elements of an array, I can do sum(array) 
or array.sum() :


With the first method

 >>> a
array([[1, 2],
        [3, 4]])

 >>> numarray.sum(a)
array([4, 6])

It seems to be impossible to sum all the elements with sum(array).

With the second,

 >>> a.sum()
10L

In this case, it's ok but :

 >>> b
array(1)

 >>> b.sum()
0L

I know that it's stupid to sum only one element but it's force me to 
plan that case in my program (and I don't want to check for each case) 
if I don't want an error.


2) When I want to replace one element in an array :

 >>> a[0,0]=1.1
 >>> a
array([[1, 2],
        [3, 4]])

I know that I created the array as an array of integer, but at least I 
can expect an error message.


Anyboby knows if these behaviour are bugs or not ? And if not, I will be 
glad the have somme explication about the choice of this behaviour.


Thanks for your help,

Jean-Luc




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