I have 2 global arrays "tab1" and "tab2" with dimensions respectively equal to 21x21 and 17x17.
I would like to assign the block of "tab1" ( indexed by [15:20,0:7]) by the block of "tab2" indexed by [7:17:2,0:7] (so with a step between elements of 1st array dimension) : I tried whith this syntax :
tab1[15:20,0:7] = tab2[7:17:2,0:7]
Unfortunately, this doesn't work, it seems that only "diagonal" (I mean one by one) elements of 15:20 are taken into account following the values of "tab2" along [7:17:2].
Is there a way to assign a subarray of "tab1" with another subarray "tab2" composed of indexes with step spaced values ?
If someone could see what's wrong or suggest another method, this would be nice.
UPDATE 1: indeed, from my last tests, it seems good but is it also the same for the assignment of block [15:20,15:20] :
tab1[15:20,15:20] = tab2[7:17:2,7:17:2]
??
ANSWER : it seems ok also for this block assignment, sorry
The assignment works as I expect.
In [1]: arr = np.ones((20,10),int)
The two blocks have the same shape:
In [2]: arr[15:20, 0:7].shape
Out[2]: (5, 7)
In [3]: arr[7:17:2, 0:7].shape
Out[3]: (5, 7)
and assigning something interesting, looks right:
In [4]: arr2 = np.arange(200).reshape(20,10)
In [5]: arr[15:20, 0:7] = arr2[7:17:2, 0:7]
In [6]: arr
Out[6]:
array([[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
...
[ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1],
[ 70, 71, 72, 73, 74, 75, 76, 1, 1, 1],
[ 90, 91, 92, 93, 94, 95, 96, 1, 1, 1],
[110, 111, 112, 113, 114, 115, 116, 1, 1, 1],
[130, 131, 132, 133, 134, 135, 136, 1, 1, 1],
[150, 151, 152, 153, 154, 155, 156, 1, 1, 1]])
I see a (5,7) block of values from arr2, skipping rows like [80, 100,...]