Python numpy生成矩阵、串联矩阵代码分享

>>> import numpy 
>>> numpy.eye(3) 
array([[ 1.,0.,0.],[ 0.,1.,1.]]) 
>>> numpy.zeros(3) 
array([ 0.,0.]) 
>>> numpy.ones(3) 
array([ 1.,1.]) 
>>> x1 = numpy.array((1,2,3)) 
>>> x1 
array([1,3]) 
>>> x2 = numpy.array([4,5,6]) 
>>> x2 
array([4,6]) 
>>> x3 = numpy.array((x1,x2)) 
>>> x3 
array([[1,3],[4,6]]) 
>>> x4 = x3.reshape(2,3) 
>>> x4 
array([[1,6]]) 
>>> x4 = x3.reshape(3,2) 
>>> x4 
array([[1,2],[3,4],[5,6]]) 
>>> x5 = numpy.row_stack(x1,x2) 
Traceback (most recent call last): 
 File "<stdin>",line 1,in <module> 
TypeError: vstack() takes exactly 1 argument (2 given) 
>>> x5 = numpy.row_stack((x1,x2)) 
>>> x5 
array([[1,6]]) 
>>> x6 = numpy.row_stack([x1,x2]) 
>>> x6 
array([[1,6]]) 
>>> x7 = numpy.row_stack((x6,x2)) 
>>> x7 
array([[1,6],6]]) 
>>> x7[0] 
array([1,3]) 
>>> x7[1] 
array([4,6]) 
>>> x7[2] 
array([4,6]) 
>>> x8 = numpy.column_stack([x1,x2,x1,x2]) 
>>> x8 
array([[1,4,1,[2,5],6,3,6]]) 
>>> x8[0] 
array([1,4]) 
>>> x8[1] 
array([2,5]) 
>>> x8[2] 
array([3,6]) 
>>> x8[3] 
Traceback (most recent call last): 
 File "<stdin>",in <module> 
IndexError: index 3 is out of bounds for axis 0 with size 3 
>>> x8[0][3] 
4 
>>> 

print np.ones((1,4))*2