Get row numbers of NumPy array having element larger than X
Let's see how to getting the row numbers of a numpy array that have at least one item is larger than a specified value X. So, for doing this task we will use numpy.where() and numpy.any() functions together.
Syntax: numpy.where(condition[, x, y])
Return: [ndarray or tuple of ndarrays] If both x and y are specified, the output array contains elements of x where condition is True, and elements from y elsewhere.
Syntax: numpy.any(a, axis = None, out = None, keepdims = class numpy._globals._NoValue at 0x40ba726c)
Return: [ndarray, optional]Output array with same dimensions as Input array, Placed with result
Example :
Arr = [[1,2,3,4,5], [10,-3,30,4,5], [3,2,5,-4,5], [9,7,3,6,5]] and X = 6 then output is [ 0, 2 ]. Here, [[1,2,3,4,5], no element is greater than 6 so output is [0]. [10,-3,30,4,5], 10 is greater than 6 so output is [0]. [3,2,5,-4,5], no element is greater than 6 so output is [0, 2]. [4,7,3,6,5]] 7 is greater than 6 so output is [0, 2].
Below is the implementation:
# importing library
import numpy
# create numpy array
arr = numpy.array([[1, 2, 3, 4, 5],
[10, -3, 30, 4, 5],
[3, 2, 5, -4, 5],
[9, 7, 3, 6, 5]
])
# declare specified value
X = 6
# view array
print("Given Array:\n", arr)
# finding out the row numbers
output = numpy.where(numpy.any(arr > X,
axis = 1))
# view output
print("Result:\n", output)
Output:
Given Array: [[ 1 2 3 4 5] [10 -3 30 4 5] [ 3 2 5 -4 5] [ 9 7 3 6 5]] Result: (array([1, 3], dtype=int64),)