np.r_ 数组合并

如果索引表达式包含逗号分隔的数组，则将它们沿第一个轴堆叠

start:stop:step  等同 np.arange(start, stop, step)

np.r_[-1:3:2, [0]*3, 5, 6]
Out[2]: array([-1,  1,  0,  0,  0,  5,  6])

np.r_[np.arange(-1,3,2), [0]*3, 5, 6]
Out[3]: array([-1,  1,  0,  0,  0,  5,  6])

start:stop:stepj 等同 np.linspace(start, stop, step, endpoint=1)

np.r_[-1:1:6j, [0]*3, 5, 6]
Out[141]: array([-1. , -0.6, -0.2,  0.2,  0.6,  1. ,  0. ,  0. ,  0. ,  5. ,  6. ])

np.r_[np.linspace(-1,1,6), [0]*3, 5, 6]
Out[142]: array([-1. , -0.6, -0.2,  0.2,  0.6,  1. ,  0. ,  0. ,  0. ,  5. ,  6. ])

np.r_['r',[1,2,3], [4,5,6]]
Out[143]: matrix([[1, 2, 3, 4, 5, 6]])

np.r_['c',[1,2,3], [4,5,6]]
Out[144]:
matrix([[1],
[2],
[3],
[4],
[5],
[6]])

np.r_['c',np.array([[0, 1, 2], [3, 4, 5]]), np.array([[0, 1, 2], [3, 4, 5]])]
Out[145]:
matrix([[0, 1, 2],
[3, 4, 5],
[0, 1, 2],
[3, 4, 5]])

np.r_['r',np.array([[0, 1, 2], [3, 4, 5]]), np.array([[0, 1, 2], [3, 4, 5]])]
Out[146]:
matrix([[0, 1, 2],
[3, 4, 5],
[0, 1, 2],
[3, 4, 5]])

np.r_['0,2,0', [1,2,3], [4,5,6]]
Out[149]:
array([[1],
[2],
[3],
[4],
[5],
[6]])

np.r_['0,2,1', [1,2,3],[4,5,6]]
Out[150]:
array([[1, 2, 3],
[4, 5, 6]])