【Python】Numpy扩充数组函数之repeat和tile用法


用repeat和tile扩充数组元素,例如

>>> import numpy as np
>>> np.arange(10)
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> a = np.arange(10)
>>> a
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> a.repeat(5)
array([0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4,
4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9,
9, 9, 9, 9])
>>> a
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> np.tile(a,2)
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>>


官方例子:

>>> from numpy import *
>>> a=array([10,20])
>>> tile(a,(3,2)) #构造3X2个copy
array([[10, 20, 10, 20],
[10, 20, 10, 20],
[10, 20, 10, 20]])
>>> tile(42.0,(3,2))
array([[ 42., 42.],
[ 42., 42.],
[ 42., 42.]])
>>>
>>> from numpy import *>>> repeat(7.,4)array([ 7.,  7.,  7.,  7.])>>> a=array([10,20])>>> a.repeat([3,2])array([10, 10, 10, 20, 20])>>> repeat(a,[3,2])array([10, 10, 10, 20, 20])>>> a=array([[10,20],[30,40]])>>> a.repeat([3,2],axis=0)array([[10, 20],       [10, 20],       [10, 20],       [30, 40],       [30, 40]])>>> a.repeat([3,2],axis=1)array([[10, 10, 10, 20, 20],       [30, 30, 30, 40, 40]])>>> 


转载出处: http://blog.csdn.net/henryghx/article/details/16906235




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