numpy.fromfunction¶
-
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)
.Parameters: function : callable
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, ifshape
were(2, 2)
, then the parameters would bearray([[0, 0], [1, 1]])
andarray([[0, 1], [0, 1]])
shape : (N,) tuple of ints
Shape of the output array, which also determines the shape of the coordinate arrays passed to function.
dtype : data-type, optional
Data-type of the coordinate arrays passed to function. By default,
dtype
is float.Returns: fromfunction : any
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 offromfunction
would match theshape
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]])