numpy.expm1()

numpy.expm1

numpy.expm1(x[, out]) =

Calculate exp(x) - 1 for all elements in the array.

Parameters:

x : array_like

Input values.

Returns:

out : ndarray

Element-wise exponential minus one: out = exp(x) - 1.

See also

log1p
log(1 + x), the inverse of expm1.

Notes

This function provides greater precision than exp(x) - 1 for small values of x.

Examples

The true value of exp(1e-10) - 1 is 1.00000000005e-10 to about 32 significant digits. This example shows the superiority of expm1 in this case.

>>> np.expm1(1e-10)
1.00000000005e-10
>>> np.exp(1e-10) - 1
1.000000082740371e-10

© 2008–2016 NumPy Developers
Licensed under the NumPy License.
https://docs.scipy.org/doc/numpy-1.10.1/reference/generated/numpy.expm1.html

在线笔记
App下载
App下载

扫描二维码

下载编程狮App

公众号
微信公众号

编程狮公众号

意见反馈
返回顶部