So i have a Numpy array and i want to average every five elements and discard the sixth element, then average out the next five elements and discard the twelfth element and so on.
I have tried using the library function np.average()but it does not allow me to discard the factor of sixth value.
For Example: I have
Input:
a=[[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18],
[19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36],
[37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54]]
Output:
a_avg=[[3,9,15],
[21,27,33],
[39,45,51]'
Also is it possible to make it dynamic to the size of array?
IIUC, you can first compute a mask to remove every 6th item.
Then reshape to have 5 elements in one dimension, compute the mean, and reshape again:
mask = np.arange(a.shape[1])%6 != 5
a[:, mask].reshape((-1,5)).mean(1).reshape((a.shape[0], -1))
output:
array([[ 3., 9., 15.],
[21., 27., 33.],
[39., 45., 51.]])
input:
array([[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18],
[19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36],
[37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54]])