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numpy.linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None)
在指定的间隔内返回均匀间隔的数字。
返回num均匀分布的样本，在[start, stop]。
这个区间的端点可以任意的被排除在外。
| Parameters(参数): |
start : scalar(标量)
The starting value of the sequence(序列的起始点).
stop : scalar
序列的结束点，除非endpoint被设置为False，在这种情况下, the sequence consists of all but the last of num + 1 evenly spaced samples(该序列包括所有除了最后的num+1上均匀分布的样本(感觉这样翻译有点坑)), 以致于stop被排除.当endpoint is False的时候注意步长的大小(下面有例子).
num : int, optional(可选)
生成的样本数，默认是50。必须是非负。
endpoint : bool, optional
如果是真，则一定包括stop，如果为False，一定不会有stop
retstep : bool, optional
If True, return (samples, step), where step is the spacing between samples.(看例子)
dtype : dtype, optional
The type of the output array. If dtype is not given, infer the data type from the other input arguments(推断这个输入用例从其他的输入中).
|
|---|
| Returns: |
samples : ndarray
There are num equally spaced samples in the closed interval [start, stop] or the half-open interval [start, stop) (depending on whether endpoint is True or False).
step : float(只有当retstep设置为真的时候才会存在)
Only returned if retstep is True
Size of spacing between samples.
|
|---|
See also
- arange
- Similar to linspace, but uses a step size (instead of the number of samples).
- arange使用的是步长，而不是样本的数量
- logspace
- Samples uniformly distributed in log space.
当endpoint被设置为False的时候
>>> import numpy as np
>>> np.linspace(1, 10, 10)
array([ 1., 2., 3., 4., 5., 6., 7., 8., 9., 10.])
>>> np.linspace(1, 10, 10, endpoint = False)
array([ 1. , 1.9, 2.8, 3.7, 4.6, 5.5, 6.4, 7.3, 8.2, 9.1])
In [4]: np.linspace(1, 10, 10, endpoint = False, retstep= True)
Out[4]: (array([ 1. , 1.9, 2.8, 3.7, 4.6, 5.5, 6.4, 7.3, 8.2, 9.1]), 0.9)
官网的例子
Examples
>>>
>>> np.linspace(2.0, 3.0, num=5)
array([ 2. , 2.25, 2.5 , 2.75, 3. ])
>>> np.linspace(2.0, 3.0, num=5, endpoint=False)
array([ 2. , 2.2, 2.4, 2.6, 2.8])
>>> np.linspace(2.0, 3.0, num=5, retstep=True)
(array([ 2. , 2.25, 2.5 , 2.75, 3. ]), 0.25)
Graphical illustration:
>>>
>>> import matplotlib.pyplot as plt
>>> N = 8
>>> y = np.zeros(N)
>>> x1 = np.linspace(0, 10, N, endpoint=True)
>>> x2 = np.linspace(0, 10, N, endpoint=False)
>>> plt.plot(x1, y, ‘o‘)
[<matplotlib.lines.Line2D object at 0x...>]
>>> plt.plot(x2, y + 0.5, ‘o‘)
[<matplotlib.lines.Line2D object at 0x...>]
>>> plt.ylim([-0.5, 1])
(-0.5, 1)
>>> plt.show()
numpy.linspace使用详解
标签：lan inf form ret add scalar show similar src
原文地址：http://www.cnblogs.com/antflow/p/7220798.html
