numpy.fromfunction(function, shape, **kwargs)[source]¶Construct an array by executing a function over each coordinate.
The resulting array therefore has a value fn(x, y, z) at
coordinate (x, y, z).
The function is called with N parameters, where N is the rank of
shape. Each parameter represents the coordinates of the array
varying along a specific axis. For example, if shape
were (2, 2), then the parameters would be
array([[0, 0], [1, 1]]) and array([[0, 1], [0, 1]])
Shape of the output array, which also determines the shape of the coordinate arrays passed to function.
Data-type of the coordinate arrays passed to function.
By default, dtype is float.
The result of the call to function is passed back directly.
Therefore the shape of fromfunction is completely determined by
function. If function returns a scalar value, the shape of
fromfunction would not match the shape parameter.
Notes
Keywords other than dtype are passed to function.
Examples
>>> np.fromfunction(lambda i, j: i == j, (3, 3), dtype=int)
array([[ True, False, False],
[False, True, False],
[False, False, True]])
>>> np.fromfunction(lambda i, j: i + j, (3, 3), dtype=int)
array([[0, 1, 2],
[1, 2, 3],
[2, 3, 4]])