Numpy MaskedArray.common_fill_value() function | Python

Last Updated : 29 Oct, 2019

numpy.MaskedArray.common_fill_value() function is used to return the common filling value between two masked arrays.If arr1.fill_value == arr2.fill_value then it returns the fill value, otherwise return None.

Syntax : numpy.ma.common_fill_value(arr1, arr2) Parameters: arr1, arr2 :[ MaskedArray ] The masked arrays for which to compare fill values. Return : [ scalar or None] The common fill value or None.

Code #1 :

Python3

# Python program explaining
# numpy.MaskedArray.common_fill_value() method 
  
# importing numpy as geek  
# and numpy.ma module as ma 
import numpy as geek 
import numpy.ma as ma 
  
# creating input arrays  
in_arr1 = geek.array([[1, 2], [ 3, -1], [ 5, -3]])
print ("1st Input array : ", in_arr1) 

in_arr2 = geek.array([[10, 20], [ 30, -10], [ 50, -30]])
print ("2nd Input array : ", in_arr2) 
  
# Now we are creating masked arrays. 
# by making  entry as invalid.  
mask_arr1 = ma.masked_array(in_arr1, mask =[[1, 0], [ 1, 0], [ 0, 0]],
                                                       fill_value = 5) 
print ("1st Masked array : ", mask_arr1) 

mask_arr2 = ma.masked_array(in_arr2, mask =[[1, 1], [ 1, 0], [ 0, 0]], 
                                                      fill_value = 5) 
print ("2nd Masked array : ", mask_arr2) 
  
# applying MaskedArray.common_fill_value    
# methods to masked array
out_arr = ma.common_fill_value(mask_arr1, mask_arr2) 
print ("common filled value : ", out_arr)

Output:

1st Input array :  [[ 1  2]
 [ 3 -1]
 [ 5 -3]]
2nd Input array :  [[ 10  20]
 [ 30 -10]
 [ 50 -30]]
1st Masked array :  [[-- 2]
 [-- -1]
 [5 -3]]
2nd Masked array :  [[-- --]
 [-- -10]
 [50 -30]]
common filled value :  5

Code #2 :

Python3

# Python program explaining
# numpy.MaskedArray.common_fill_value() method 
  
# importing numpy as geek  
# and numpy.ma module as ma 
import numpy as geek 
import numpy.ma as ma 
  
# creating input arrays  
in_arr1 = geek.array([[1, 2], [ 3, -1], [ 5, -3]])
print ("1st Input array : ", in_arr1) 

in_arr2 = geek.array([[10, 20], [ 30, -10], [ 50, -30]])
print ("2nd Input array : ", in_arr2) 
  
# Now we are creating masked arrays. 
# by making  entry as invalid.  
mask_arr1 = ma.masked_array(in_arr1, mask =[[1, 0], [ 1, 0], [ 0, 0]],
                                                      fill_value = 5) 
print ("1st Masked array : ", mask_arr1) 

mask_arr2 = ma.masked_array(in_arr2, mask =[[1, 1], [ 1, 0], [ 0, 0]],
                                                     fill_value = 10) 
print ("2nd Masked array : ", mask_arr2) 
  
# applying MaskedArray.common_fill_value    
# methods to masked array
out_arr = ma.common_fill_value(mask_arr1, mask_arr2) 
print ("common filled value : ", out_arr)

Output:

1st Input array :  [[ 1  2]
 [ 3 -1]
 [ 5 -3]]
2nd Input array :  [[ 10  20]
 [ 30 -10]
 [ 50 -30]]
1st Masked array :  [[-- 2]
 [-- -1]
 [5 -3]]
2nd Masked array :  [[-- --]
 [-- -10]
 [50 -30]]
common filled value :  None