I have a 2D array with indices refering to another array:

indexarray = np.array([[0,0,1,1],
                       [1,2,3,0]])

The array which these indices refer to is:

valuearray = np.array([8,7,6,5])

I would like to get an array with the numbers from valuearray in the shape of indexarray, each item in this array corresponds to the value in valuearray with the index on the same location in indexarray, ie:

targetarray = np.array([[8,8,7,7],
                        [7,6,5,8]])

How can I do this without iteration?

What I do now to achieve this is:

np.apply_along_axis(func1d = lambda row: valuearray[row],axis=0,arr = indexarray)

If there is a simpler way, I am interested.

CodePudding user response：

One way is to flatten the index array and get the values and reshape it back as follows.

targetarray = valuearray[indexarray.flatten()].reshape(indexarray.shape)