linspace生成有序列表，重点在数据范围与数据个数上 linspace(0,1,11)，即从0到1闭区间，划分为11个数据点
>>> import numpy
as np
>>> a
= np
.linspace
(0,1,10)
>>> a
array
([0. , 0.11111111, 0.22222222, 0.33333333, 0.44444444,
0.55555556, 0.66666667, 0.77777778, 0.88888889, 1. ])
>>> a
= np
.linspace
(0,1,11)
>>> a
array
([0. , 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1. ])
