Python numpy.exp() 到底做了什么？
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What exactly does numpy.exp() do?
提问by bugsyb
I'm very confused as to what np.exp() actually does. In the documentation it says that it: "Calculates the exponential of all elements in the input array." I'm confused as to what exactly this means. Could someone give me more information to what it actually does?
我对 np.exp() 的实际作用感到非常困惑。在文档中它说：“计算输入数组中所有元素的指数。” 我很困惑这到底是什么意思。有人能给我更多关于它实际作用的信息吗？
回答by Tom
It calculates exfor each xin your list where eis Euler's number (approximately 2.718). In other words, np.exp(range(5))is similar to [math.e**x for x in range(5)].
它为列表中的每个x计算e x，其中e是欧拉数（约 2.718）。换句话说，类似于。np.exp(range(5))[math.e**x for x in range(5)]
回答by machine yearning
The exponential function is e^xwhere eis a mathematical constant called Euler's number, approximately 2.718281. This value has a close mathematical relationship with piand the slope of the curve e^xis equal to its value at every point. np.exp()calculates e^xfor each value of xin your input array.
指数函数是e^x其中e是一个称为欧拉数的数学常数，大约为2.718281。该值具有密切的数学关系，pi曲线的斜率e^x在每一点都等于其值。np.exp()计算输入数组中的e^x每个值x。
回答by Arijit
exp(x) = e^x where e= 2.718281(approx)
exp(x) = e^x 其中 e= 2.718281(approx)
import numpy as np
ar=np.array([1,2,3])
ar=np.exp(ar)
print ar
output of the Sample Code-> [ 2 7 20]
示例代码的输出-> [ 2 7 20]
