numpy.median() in Python
Last Updated :
28 Nov, 2018
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numpy.median(arr, axis = None)
: Compute the median of the given data (array elements) along the specified axis.
How to calculate median?
- Given data points.
- Arrange them in ascending order
- Median = middle term if total no. of terms are odd.
- Median = Average of the terms in the middle (if total no. of terms are even)
Parameters : arr : [array_like]input array. axis : [int or tuples of int]axis along which we want to calculate the median. Otherwise, it will consider arr to be flattened(works on all the axis). axis = 0 means along the column and axis = 1 means working along the row. out : [ndarray, optional] Different array in which we want to place the result. The array must have the same dimensions as expected output. dtype : [data-type, optional]Type we desire while computing median. Results : Median of the array (a scalar value if axis is none) or array with median values along specified axis.Code #1:
# Python Program illustrating
# numpy.median() method
import numpy as np
# 1D array
arr = [20, 2, 7, 1, 34]
print("arr : ", arr)
print("median of arr : ", np.median(arr))
arr : [20, 2, 7, 1, 34] median of arr : 7.0Code #2:
# Python Program illustrating
# numpy.median() method
import numpy as np
# 2D array
arr = [[14, 17, 12, 33, 44],
[15, 6, 27, 8, 19],
[23, 2, 54, 1, 4, ]]
# median of the flattened array
print("\nmedian of arr, axis = None : ", np.median(arr))
# median along the axis = 0
print("\nmedian of arr, axis = 0 : ", np.median(arr, axis = 0))
# median along the axis = 1
print("\nmedian of arr, axis = 1 : ", np.median(arr, axis = 1))
out_arr = np.arange(3)
print("\nout_arr : ", out_arr)
print("median of arr, axis = 1 : ",
np.median(arr, axis = 1, out = out_arr))
median of arr, axis = None : 15.0 median of arr, axis = 0 : [15. 6. 27. 8. 19.] median of arr, axis = 1 : [17. 15. 4.] out_arr : [0 1 2] median of arr, axis = 1 : [17 15 4]