Cannot modify numpy 2d array

Question

I am trying to modify the boolarr numpy array depending on the contents of the reducedMatrix array. It is supposed to change the boolean value of the boolarr to False if reducedMatrix is not a 0 or a -1.

reducedMatrix = np.load(reducedweightmatrix)

boolarr = np.ones(shape=(len(reducedMatrix),len(reducedMatrix)),dtype="bool")

for y,yelement in enumerate(reducedMatrix):
    for x,xelement in enumerate(yelement):
        if(xelement != -1 and xelement != 0):
            print(x)
            print(y)
            print("\n")
            boolarr[y,x] == False

print(reducedMatrix)
print(boolarr)

The log keeps on showing the following:

[[-1  5  5  0  0]
 [ 5 -1  0  0  0]
 [ 5  0 -1  0  5]
 [ 0  0  0 -1  0]
 [ 0  0  5  0 -1]]
[[ True  True  True  True  True]
 [ True  True  True  True  True]
 [ True  True  True  True  True]
 [ True  True  True  True  True]
 [ True  True  True  True  True]]

What am I doing wrong?

Nils Werner · Accepted Answer · 2018-08-10 10:08:15Z

1

There is no need to edit boolarray elementwise when you can just create it in one vectorized line:

boolarray = (reducedMatrix == 0) | (reducedMatrix == -1)
# array([[ True, False, False,  True,  True],
#        [False,  True,  True,  True,  True],
#        [False,  True,  True,  True, False],
#        [ True,  True,  True,  True,  True],
#        [ True,  True, False,  True,  True]])

edited Aug 10, 2018 at 10:08

answered Aug 10, 2018 at 9:28

Nils Werner

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Comments

Bruno Lubascher · Accepted Answer · 2018-08-10 09:25:12Z

1

You need to change

boolarr[y,x] == False

into

boolarr[y,x] = False

answered Aug 10, 2018 at 9:25

Bruno Lubascher

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