将一维数组重塑为蒙版二维数组

Question

OK so I have this 2D array:

print indgrid

[[0 6 9 3 1]
[5 9 7 4 5]
[2 8 3 8 4]
[5 6 2 6 8]
[5 3 7 7 0]]

I then apply a mask to it:

print mask

[[False False  True False False]
 [False  True  True  True False]
 [ True  True  True  True  True]
 [False  True  True  True False]
 [False False  True False False]]


print indgrid[mask]

[9 9 7 4 2 8 3 8 4 6 2 6 7]

So this is now a 1D array of values that have been taken out of the indgrid array. I then want to perform some calculations on these values and then when I am done, put the values calculated from each element into a 2D array which is the same shape as the indgrid array, so I would end up with this:

[[ 0 0 f 0 0 ]
[ 0 f f f 0 ]
[ f f f f f ]
[ 0 f f f 0]
[ 0 0 f 0 0 ]]

where f just represents a float that I have calculated. What is the best way of doing this? Thanks.

Answer 1

Forgive the terrible variable names:

f_values = some_function_of(indgrid[mask])
result = np.zeros(indgrid.shape)
result[mask] = f_values