python numpy教程-刘一痕-ChinaUnix博客 http://blog.chinaunix.net/uid-21633169-id-4408596.html
一个例子中 range 和arange的区别!
b = linspace(0,pi,3)
这部分的意思,从0 - pi ,分成三个的列表
结果[0,pi/2,pi]
array([ 0, 1, 8, 27, 64, 125, 216, 343, 512, 729])
>>> a[:6:2] = -1000 # equivalent to a[0:6:2] = -1000; from start to position 6, exclusive, set every 2nd element to -1000
>>> a
array([-1000, 1, -1000, 27, -1000, 125, 216, 343, 512, 729])
>>> a[ : :-1] # reversed a -1 表示翻转列表
array([ 729, 512, 343, 216, 125, -1000, 27, -1000, 1, -1000])