Replace sub part of matrix by another small matrix in numpy

Question

I am new to Numpy and want to replace part of a matrix. For example, I have two matrices, A, B generated by numpy

In [333]: A = ones((5,5))

In [334]: A
Out[         


        

Answer 1

For the first one:

In [13]: A[-B.shape[0]:, -B.shape[1]:] = B                              

In [14]: A
Out[14]: 
array([[ 1. ,  1. ,  1. ,  1. ,  1. ],                                  
       [ 1. ,  1. ,  1. ,  1. ,  1. ],                                  
       [ 1. ,  1. ,  1. ,  1. ,  1. ],                                  
       [ 1. ,  1. ,  1. ,  0.1,  0.2],                                  
       [ 1. ,  1. ,  1. ,  0.3,  0.4]])   

For second:

In [15]: A = np.ones((5,5))                                             

In [16]: A[:B.shape[0], -B.shape[1]:] = B                               

In [17]: A
Out[17]: 
array([[ 1. ,  1. ,  1. ,  0.1,  0.2],                                  
       [ 1. ,  1. ,  1. ,  0.3,  0.4],                                  
       [ 1. ,  1. ,  1. ,  1. ,  1. ],                                  
       [ 1. ,  1. ,  1. ,  1. ,  1. ],                                  
       [ 1. ,  1. ,  1. ,  1. ,  1. ]])