Python numpy.tp()

numpy.ptp()函数在统计学中发挥了重要作用，它可以找出给定数字的范围。范围 = 最大值 – 最小值。

语法 : ndarray.ptp(arr, axis=None, out=None)
参数 :
arr :输入阵列。
axis :轴，我们希望沿着这个轴得到范围值。否则，它将认为Arr是平坦的（在所有轴上工作）。 axis = 0意味着沿着列工作， axis = 1意味着沿着行工作。
out :[ndarray, optional]不同的数组，我们想把结果放在其中。该数组必须具有与预期输出相同的尺寸。
返回 :数组的范围（如果坐标轴为零，则为标量值）或沿指定坐标轴的数值范围的数组。

代码#1：工作

# Python Program illustrating
# numpy.ptp() method
   
import numpy as np
   
# 1D array
arr = [1, 2, 7, 20, np.nan]
print("arr : ", arr)
print("Range of arr : ", np.ptp(arr))
 
# 1D array
arr = [1, 2, 7, 10, 16]
print("arr : ", arr)
print("Range of arr : ", np.ptp(arr))

输出 :

arr :  [1, 2, 7, 20, nan]
Range of arr :  nan
arr :  [1, 2, 7, 10, 16]
Range of arr :  15

代码 #2 :

# Python Program illustrating
# numpy.ptp() method
 
import numpy as np
 
# 3D array
arr = [[14, 17, 12, 33, 44], 
       [15, 6, 27, 8, 19],
       [23, 2, 54, 1, 4,]]
print("\narr : \n", arr)
    
# Range of the flattened array
print("\nRange of arr, axis = None : ", np.ptp(arr))
    
# Range along the first axis
# axis 0 means vertical
print("Range of arr, axis = 0 : ", np.ptp(arr, axis = 0))
    
# Range along the second axis
# axis 1 means horizontal
print("Min of arr, axis = 1 : ", np.ptp(arr, axis = 1)) 

输出 :

arr : 
 [[14, 17, 12, 33, 44], [15, 6, 27, 8, 19], [23, 2, 54, 1, 4]]

Range of arr, axis = None :  53
Range of arr, axis = 0 :  [ 9 15 42 32 40]
Min of arr, axis = 1 :  [32 21 53]

代码 #3 :

# Python Program illustrating
# numpy.ptp() method
 
import numpy as np
 
arr1 = np.arange(5)
print("\nInitial arr1 : ", arr1)
  
# using out parameter
np.ptp(arr, axis = 0, out = arr1)
  
print("Changed arr1(having results) : ", arr1)

输出 :

Initial arr1 :  [0 1 2 3 4]
Changed arr1(having results) :  [ 9 15 42 32 40]