I have a 3D numpy array A of shape 10 x 5 x 3. I also have a vector B of length 3 (length of last axis of A). I want to compare each A[:,:,i] against B[i] where i = 0:2 and replace all values A[:,:,i] > B[i] with B[i].
Is there a way to achieve this without a for loop.
Edit: I tried the argmax across i = 0:2 using a for loop
python replace values in 2d numpy array
You can use numpy.minimum to accomplish this. It returns the element-wise minimum between two arrays. If the arrays are different sizes (such as in your case), then the arrays are automatically broadcast to the correct size prior to comparison.
A = numpy.random.rand(1,2,3)
# array([[[ 0.79188 , 0.32707664, 0.18386629],
# [ 0.4139146 , 0.07259663, 0.47604274]]])
B = numpy.array([0.1, 0.2, 0.3])
C = numpy.minimum(A, B)
# array([[[ 0.1 , 0.2 , 0.18386629],
# [ 0.1 , 0.07259663, 0.3 ]]])
Or as suggested by @Divakar if you want to do in-place replacement:
numpy.minimum(A, B, out=A)
