Numpy MaskedArray.dot () Function | python

numpy.MaskedArray.dot() is used to compute the dot product of two masked arrays.

Syntax: numpy.ma.dot (arr1, arr2, strict = False)

Parameters:
arr1, arr2: [ndarray] Inputs arrays.
strict: [bool, optional] Whether masked data are propagated (True) or set to 0 (False) for the computation. Default is False.

Return: [ndarray] The dot product of arr1 and arr2.

Code # 1:

# Python program explaining
# numpy.MaskedArray.dot () method

 
# import numy as a geek
# and the numpy.ma module as ma

import numpy as geek 

import numpy.ma as ma 

 
# creating input arrays

in_arr1 = geek.array ([[ 1 , 2 ], [ 3 , 4 ]])

print ( "1st Input array:" , in_arr1) 

 

in_arr2 = geek.array ([[ - 1 , - 2 ], [ - 3 , - 4 ]]) 

print ( "2nd Input array:" , in_arr2)  < / p>

 

 
# We are now creating a masked array.
# invalidating the post

mask_arr1 = ma.masked_array (in_arr1, mask = [[ 1 , 0 ], [ 0 , 1 ]]) 

print ( "1st Masked array:" , mask_arr1) 

  

mask_arr2 = ma.masked_array ( in_arr2, mask  = [[ 0 , 1 ], [ 0 , 0 ]]) 

print ( "2nd Masked array:" , mask_arr2 ) 

 
# applying MaskedArray.dot methods
# to masked array

out_arr = ma.dot (mask_arr1, mask_arr2) 

print ( "Dot product of two arrays:" , out_arr) 

Exit:

1st Input array: [[1 2] [3 4]] 2nd Input array: [[-1 -2] [-3 -4]] 1st Masked array: [[- 2] [3 -]] 2nd Masked array: [[-1 -] [-3 -4]] Dot product of two arrays: [[-6 -8] [-3 -]]

Code # 2:

# Python program explaining
# numpy .MaskedArray.dot () method

 
# import numy as a geek
# and the 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 ([[ 1 , 0 , 3 ], [ 4 , 1 , 6 ]]) 

print ( "2nd Input array:" , in_arr2) 

 

  
# We now create a masked array.
# invalidate the post

mask_arr1 = ma.masked_array (in_arr1, mask = [[ 1 , 0 ], [ 0 , 1 ], [ 0 , 0 ]]) 

print ( "1st Masked array:" , mask_arr1) 

 

mask_arr2 = ma.masked_array (in_arr2, mask = [[ 0 , 0 , 0 ], [ 0 , 0 , 1 ]]) 

print ( "2nd Masked array:" , mask_arr2) 

  # applying the MaskedArray.dot methods
# into the masked array

out_arr = ma.dot (mask_arr1, mask_arr2) 

print ( "Dot product of two arrays:" , out_arr) 

Output:

 1st Input array: [[1 2] [3 -1] [5 -3]] 2nd Input array: [[1 0 3] [4 1 6]] 1st Masked array: [[- 2 ] [3 -] [5 -3]] 2nd Masked array: [[1 0 3] [4 1 -]] Dot product of two arrays: [[8 2 -] [3 0 9] [-7 -3 15]]