Numpy MaskedArray.average() function | Python
Last Updated :
13 Oct, 2019
numpy.MaskedArray.average()
function is used to return the weighted average of array over the given axis.
Syntax : numpy.ma.average(arr, axis=None, weights=None, returned=False)
Parameters:
arr :[ array_like] Input masked array whose data to be averaged. Masked entries are not taken into account in the computation.
axis :[ int, optional] Axis along which to average arr. If None, averaging is done over the flattened array.
weights : [array_like, optional] The importance that each element has in the computation of the average. If weights=None, then all data in arr are assumed to have a weight equal to one. If weights is complex, the imaginary parts are ignored.
returned :[ bool, optional] It indicates whether a tuple (result, sum of weights) should be returned as output (True), or just the result (False). Default is False.
Return : [ scalar or MaskedArray] The average along the specified axis. When returned is True, return a tuple with the average as the first element and the sum of the weights as the second element.
Code #1 :
import numpy as geek
import numpy.ma as ma
in_arr = geek.array([[ 1 , 2 ], [ 3 , - 1 ], [ 5 , - 3 ]])
print ( "Input array : " , in_arr)
mask_arr = ma.masked_array(in_arr, mask = [[ 1 , 0 ], [ 1 , 0 ], [ 0 , 0 ]])
print ( "Masked array : " , mask_arr)
out_arr = ma.average(mask_arr)
print ( "normal average of masked array : " , out_arr)
|
Output:
Input array : [[ 1 2]
[ 3 -1]
[ 5 -3]]
Masked array : [[-- 2]
[-- -1]
[5 -3]]
normal average of masked array : 0.75
Code #2 :
import numpy as geek
import numpy.ma as ma
in_arr = geek.array([[ 1 , 2 ], [ 3 , - 1 ], [ 5 , - 3 ]])
print ( "Input array : " , in_arr)
mask_arr = ma.masked_array(in_arr, mask = [[ 1 , 0 ], [ 1 , 0 ], [ 0 , 0 ]])
print ( "Masked array : " , mask_arr)
out_arr = ma.average(mask_arr, weights = [[ 0 , 1 ], [ 0 , 2 ], [ 3 , 1 ]])
print ( "weighted average of masked array : " , out_arr)
|
Output:
Input array : [[ 1 2]
[ 3 -1]
[ 5 -3]]
Masked array : [[-- 2]
[-- -1]
[5 -3]]
weighted average of masked array : 1.7142857142857142
Share your thoughts in the comments
Please Login to comment...