import numpy as np
np.random.seed(1)
A = np.random.random((10,15))
B = np.random.random((10,15))
import numpy as np
np.random.seed(1)
A = np.random.random((10,15))
B = np.random.random((10,15))
#### 1. What is the value of the second row and third column of A?
print( A[1,2] )
# 0.558689828446
#### 2. What is the average value of the fifth row of A?
print( A[4].mean() )
print( np.average(A[4]) )
print( A.mean(axis=1)[4] )
# 0.487058290328
#### 3. What is the sum of all elements of A-B?
print( (A-B).sum() )
print( A.sum() - B.sum() )
# -8.23869499888
#### 4. What is the size(not shape) of AB'?
print( A.dot(B.T).size )
print( np.dot(A, B.T).size )
# 100
#### 5. What is the sum of the second column of BA'?
print( np.dot(B, A.T).sum(axis=0)[1] )
# 40.964734835
#### 6. What is the sum of diagonals of BA'?
print( np.dot(B, A.T).diagonal().sum() )
# 39.7123707064
