np.linspace用法

np.linspace主要用来创建等差数列

对于数列，若满足：

 

则称该数列为等差数列。其中，公差d为一常数，n为正整数。

 

numpy.linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None, axis=0)
Return evenly spaced numbers over a specified interval.
(在start和stop之间返回均匀间隔的数据)
Returns num evenly spaced samples, calculated over the interval [start, stop].
(返回的是 [start, stop]之间的均匀分布)
The endpoint of the interval can optionally be excluded.
Changed in version 1.16.0: Non-scalar start and stop are now supported.
(可以选择是否排除间隔的终点)

 

参数含义：

start:返回样本数据开始点
stop:返回样本数据结束点
num:生成的样本数据量，默认为50
endpoint：True则包含stop；False则不包含stop
retstep：If True, return (samples, step), where step is the spacing between samples.(即如果为True则结果会给出数据间隔)
dtype：输出数组类型
axis：0(默认)或-1

 

使用例子

>>> np.linspace(-1, 1, 20)
array([-1.        , -0.89473684, -0.78947368, -0.68421053, -0.57894737,
       -0.47368421, -0.36842105, -0.26315789, -0.15789474, -0.05263158,
        0.05263158,  0.15789474,  0.26315789,  0.36842105,  0.47368421,
        0.57894737,  0.68421053,  0.78947368,  0.89473684,  1.        ])
>>>
>>> np.linspace(-1, 1, 20, endpoint=False)
array([-1. , -0.9, -0.8, -0.7, -0.6, -0.5, -0.4, -0.3, -0.2, -0.1,  0. ,
        0.1,  0.2,  0.3,  0.4,  0.5,  0.6,  0.7,  0.8,  0.9])
>>>
>>>
>>> np.linspace(-1, 1, 20, retstep=True)
(array([-1.        , -0.89473684, -0.78947368, -0.68421053, -0.57894737,
       -0.47368421, -0.36842105, -0.26315789, -0.15789474, -0.05263158,
        0.05263158,  0.15789474,  0.26315789,  0.36842105,  0.47368421,
        0.57894737,  0.68421053,  0.78947368,  0.89473684,  1.        ]), 0.10526315789473684)
>>>