Python中的 numpy.absolute()

numpy.absolute(arr, out = None, ufunc 'absolute') ：这个数学函数帮助用户计算每个元素的绝对值。对于复数输入，a + ib，绝对值为$\sqrt { a^2 + b^2 }$ .

参数 ：

arr  : [array_like] Input array or object whose elements, we need to test.

返回 ：

An array with absolute value of each array.  

代码#1：工作

# Python program explaining
# absolute () function
  
import numpy as np
  
arr1 = [1, -3, 15, -466]
print ("Absolute Value of arr1 : \n",
                    np.absolute(arr1))
  
arr2 = [23 , -56]
print ("\nAbsolute Value of arr2 : \n",
                        np.absolute(arr2))

输出 ：

Absolute Value of arr1 : 
 [  1   3  15 466]

Absolute Value of arr2 : 
 [23 56]

代码 #2：处理复数

# Python program explaining
# absolute () function
  
import numpy as np
  
a = 4 + 3j
print("Absolute(4 + 3j) : ",
             np.absolute(a))
  
b = 16 + 13j
print("\nAbsolute value(16 + 13j) : ",
                        np.absolute(b))

输出 ：

Absolute(4 + 3j) :  5.0

Absolute value(16 + 13j) :  20.6155281281

代码 #3：numpy.absolute() 的图形表示

# Python program explaining
# absolute () function
  
import numpy as np
import matplotlib.pyplot as plt
  
a = np.linspace(start = -5, stop = 5,
                num = 6, endpoint = True)
                  
print("Graphical Representation : \n",
                        np.absolute(a))
  
plt.title("blue : with absolute\nred : without absolute")
plt.plot(a, np.absolute(a))
  
plt.plot(a, a, color = 'red')
plt.show()

输出 ：

Graphical Representation : 
 [ 5.  3.  1.  1.  3.  5.]

参考 ：
https://docs.scipy.org/doc/numpy-1.13.0/reference/generated/numpy.absolute.html
.