numpy.inf - numpy.infty

numpy.inf - numpy.infty

1. numpy.inf

IEEE 754 floating point representation of (positive) infinity.

infinity /ɪnˈfɪnəti/：n. 無窮，無限大，無限距
aliase：n. 別名

1.1 Returns

y : float
A floating point representation of positive infinity.
正無窮大的浮點表示。

NumPy uses the IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754). This means that Not a Number is not equivalent to infinity. Also that positive infinity is not equivalent to negative infinity. But infinity is equivalent to positive infinity.
NumPy 使用 IEEE Standard for Binary Floating-Point for Arithmetic (IEEE 754)。這意味着 Not a Number 不等於無窮大。同樣，正無窮大不等於負無窮大。但是無窮大等於正無窮大。

Inf, Infinity, PINF and infty are aliases for inf.

1.2 Examples

(pt-1.4_py-3.6) yongqiang@yongqiang:~$ python
Python 3.6.10 |Anaconda, Inc.| (default, May  8 2020, 02:54:21)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import numpy as np
>>> np.inf
inf
>>>
>>> -np.inf
-inf
>>>
>>> np.array([1]) / 0.
array([inf])
>>>
>>> exit()
(pt-1.4_py-3.6) yongqiang@yongqiang:~$

2. numpy.infty

IEEE 754 floating point representation of (positive) infinity.
IEEE 754 浮點表示 (正) 無窮大。

Use inf because Inf, Infinity, PINF and infty are aliases for inf.
使用 inf 是因爲 Inf，Infinity，PINF 和 infty 是 inf 的別名。