极客教程python numpy.percentile()
numpy.percentile()用于计算给定数据（数组元素）沿指定轴的第n个百分位数的函数。
语法 : numpy.percentile(arr, n, axis=None, out=None)
参数 :
arr :输入阵列。
n :百分值。
axis :我们想沿着这个轴来计算百分位值。否则，它将认为Arr是平坦的（在所有轴上工作）。 axis = 0意味着沿列工作， axis = 1意味着沿行工作。
out :不同的数组，我们要把结果放在其中。该数组必须具有与预期输出相同的尺寸。
返回 :数组的第n个百分位数（如果轴为零，则为标量值），或者沿指定轴的百分位数的数组。
**代码 #1 : **
# Python Program illustrating
# numpy.percentile() method
import numpy as np
# 1D array
arr = [20, 2, 7, 1, 34]
print("arr : ", arr)
print("50th percentile of arr : ",
np.percentile(arr, 50))
print("25th percentile of arr : ",
np.percentile(arr, 25))
print("75th percentile of arr : ",
np.percentile(arr, 75))
Python
输出 :
arr : [20, 2, 7, 1, 34]
50th percentile of arr : 7.0
25th percentile of arr : 2.0
75th percentile of arr : 20.0
Python
代码 #2 :
# Python Program illustrating
# numpy.percentile() method
import numpy as np
# 2D array
arr = [[14, 17, 12, 33, 44],
[15, 6, 27, 8, 19],
[23, 2, 54, 1, 4,]]
print("\narr : \n", arr)
# Percentile of the flattened array
print("\n50th Percentile of arr, axis = None : ",
np.percentile(arr, 50))
print("0th Percentile of arr, axis = None : ",
np.percentile(arr, 0))
# Percentile along the axis = 0
print("\n50th Percentile of arr, axis = 0 : ",
np.percentile(arr, 50, axis =0))
print("0th Percentile of arr, axis = 0 : ",
np.percentile(arr, 0, axis =0))
Python
输出 :
arr :
[[14, 17, 12, 33, 44], [15, 6, 27, 8, 19], [23, 2, 54, 1, 4]]
50th Percentile of arr, axis = None : 15.0
0th Percentile of arr, axis = None : 1.0
50th Percentile of arr, axis = 0 : [15. 6. 27. 8. 19.]
0th Percentile of arr, axis = 0 : [14. 2. 12. 1. 4.]
50th Percentile of arr, axis = 1 : [17. 15. 4.]
0th Percentile of arr, axis = 1 : [12. 6. 1.]
Python
代码 #3 :
# Python Program illustrating
# numpy.percentile() method
import numpy as np
# 2D array
arr = [[14, 17, 12, 33, 44],
[15, 6, 27, 8, 19],
[23, 2, 54, 1, 4,]]
print("\narr : \n", arr)
# Percentile along the axis = 1
print("\n50th Percentile of arr, axis = 1 : ",
np.percentile(arr, 50, axis =1))
print("0th Percentile of arr, axis = 1 : ",
np.percentile(arr, 0, axis =1))
print("\n0th Percentile of arr, axis = 1 : \n",
np.percentile(arr, 50, axis =1, keepdims=True))
print("\n0th Percentile of arr, axis = 1 : \n",
np.percentile(arr, 0, axis =1, keepdims=True))
Python
输出 :
arr :
[[14, 17, 12, 33, 44], [15, 6, 27, 8, 19], [23, 2, 54, 1, 4]]
0th Percentile of arr, axis = 1 :
[[17.]
[15.]
[ 4.]]
0th Percentile of arr, axis = 1 :
[[12.]
[ 6.]
[ 1.]]
Python