The fromfunction() function in Python constructs an array by executing a function over each coordinate. The output array has a value fn(x, y, z) at the (x, y, z) coordinate.
numpy.fromfunction(function, shape, *, dtype=<class 'float'>)
The fromfunction() function takes the following parameter values:
function: This represents the function called with N parameters. Here, N represents the rank of the shape.
shape: This represents an output array’s shape. This also determines the shape of the coordinate arrays passed to function.
dtype: This represents the data type of the coordinate arrays passed to function. This is optional, and by default, dtype is a float.
fromfunction() outputs an array. The result of the call to function is passed back directly. Therefore, the shape of the output array is completely determined by function.
import numpy as np# implementing the fromfunction() functionmyarray = np.fromfunction(lambda x, y: x + y, (2, 2), dtype=int)print(myarray)
Line 1: We import the numpy module.
Line 4: We implement the fromfunction() function on a lambda function that has a 2D array with an integer data type. We assigned the output to a variable, myarray.
Line 6: We print myarray.