Python 中的 numpy.log1p()
哎哎哎:# t0]https://www . geeksforgeeks . org/num py-log 1p-python/
numpy.log1p(arr，out = None，*其中= True，casting = 'same_kind '，order = 'K '，dtype = None，ufunc 'log1p') : 这个数学函数帮助用户计算出x+1 的自然对数值，其中 x 属于所有输入数组元素。
-
log1p is reverse of exp(x) – 1.
参数:
```py array : [array_like]Input array or object. out : [ndarray, optional]Output array with same dimensions as Input array, placed with result. **kwargs : allows you to pass keyword variable length of argument to a function. It is used when we want to handle named argument in a function. where : [array_like, optional]True value means to calculate the universal functions(ufunc) at that position, False value means to leave the value in the output alone.
```
返回:
```py An array with natural logarithmic value of x + 1; where x belongs to all elements of input array.
```
代码 1:工作
```py
Python program explaining
log1p() function
import numpy as np
in_array = [1, 3, 5] print ("Input array : ", in_array)
out_array = np.log1p(in_array) print ("Output array : ", out_array) ```
输出:
```py Input array : [1, 3, 5] Output array : [ 0.69314718 1.38629436 1.79175947]
```
代码 2:图形表示
```py
Python program showing
Graphical representation of
log1p() function
import numpy as np import matplotlib.pyplot as plt
in_array = [1, 1.2, 1.4, 1.6, 1.8, 2] out_array = np.log1p(in_array)
print ("out_array : ", out_array)
y = [1, 1.2, 1.4, 1.6, 1.8, 2] plt.plot(in_array, y, color = 'blue', marker = "*")
red for numpy.log1xp()
plt.plot(out_array, y, color = 'red', marker = "o") plt.title("numpy.log1p()") plt.xlabel("X") plt.ylabel("Y") plt.show() ```
输出:
py out_array : [ 0.69314718 0.78845736 0.87546874 0.95551145 1.02961942 1.09861229]
参考文献: https://docs . scipy . org/doc/numpy-1 . 13 . 0/reference/generated/numpy . exp . html 。
