Last Updated : 11 Jul, 2025
The numpy.multiply()
is a numpy function in Python which is used to find element-wise multiplication of two arrays or scalar (single value). It returns the product of two input array element by element.
Syntax:
numpy.multiply(arr1, arr2, out=None, where=True, casting='same_kind', order='K', dtype=None, subok=True)
Parameters:
arr1
(array_like or scalar): First input array.arr2
(array_like or scalar): Second input array.dtype
(optional): Desired type of the returned array. By default dtype of arr1
is used.out
(optional, ndarray): A location where result is stored. If not provided a new array is created.where
(optional, array_like): A condition to find where multiplication should happen. If True
multiplication occurs at that position and if False
value in output remains unchanged.Return: ndarray
(El
ement-wise product of arr1
and arr2
).
in_num1
andin_num2
using multiply
and stores the result in out_num
.
import numpy as geek
in_num1 = 4
in_num2 = 6
print ("1st Input number : ", in_num1)
print ("2nd Input number : ", in_num2)
out_num = geek.multiply(in_num1, in_num2)
print ("output number : ", out_num)
Output:
Multiplying a Scalar with a scalar Example 2: Multiplying a Scalar with an ArrayWhen one of the inputs is a scalar it is multiplied with each element of the array. This operation is commonly used for scaling or adjusting values in an array. Here Scalar value 5
is multiplied with each element 1,2,3.
import numpy as geek
in_arr = geek.array([1, 2, 3])
scalar_value = 5
result_arr = geek.multiply(in_arr, scalar_value)
print(result_arr)
Output:
Example 3: Element-wise Multiplication of Arrays[ 5 10 15]
When both inputs are arrays of the same shape numpy.multiply()
multiplies corresponding elements together. This operation is performed element by element.
import numpy as geek
in_arr1 = geek.array([[2, -7, 5], [-6, 2, 0]])
in_arr2 = geek.array([[0, -7, 8], [5, -2, 9]])
print ("1st Input array : ", in_arr1)
print ("2nd Input array : ", in_arr2)
out_arr = geek.multiply(in_arr1, in_arr2)
print ("Resultant output array: ", out_arr)
Output
Multiplying a Scalar with an ArrayIn above example corresponding elements from in_arr1
and in_arr2
are multiplied:
numpy.multiply()
supports broadcasting which means it can multiply arrays with different shapes as long as they are compatible for broadcasting rules.
import numpy as geek
in_arr1 = geek.array([1, 2, 3])
in_arr2 = geek.array([[4], [5], [6]])
result_arr = geek.multiply(in_arr1, in_arr2)
print(result_arr)
Output:
Arrays with Different ShapesIn this example in_arr1
is broadcasted to match the shape of in_arr2
for element-wise multiplication.
Example 5: UsingTo understand broadcasting you can refer to this article: NumPy Array Broadcasting
out
Parameter
We can specify an output array where result of the multiplication will be stored. This avoids creating a new array and can help save memory when working with large datasets.
Python
import numpy as geek
in_arr1 = geek.array([1, 2, 3])
in_arr2 = geek.array([4, 5, 6])
output_arr = geek.empty_like(in_arr1)
geek.multiply(in_arr1, in_arr2, out=output_arr)
print(output_arr)
Output:
[ 4 10 18]
Result of element-wise multiplication is stored in output_arr
instead of creating a new array. By mastering numpy.multiply()
we can efficiently handle element-wise multiplication across arrays and scalars.
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