Function make_linear_combination

modAL/utils/combination.py:8–34

Takes the given functions and makes a function which returns the linear combination of the output of original functions. It works well with functions returning numpy arrays of the same shape. Args: *functions: Base functions for the linear combination.The functions shall have t

(*functions: Callable, weights: Optional[Sequence] = None)

def make_linear_combination(*functions: Callable, weights: Optional[Sequence] = None) -> Callable:
    """
    Takes the given functions and makes a function which returns the linear combination of the output of original
    functions. It works well with functions returning numpy arrays of the same shape.

    Args:
        *functions: Base functions for the linear combination.The functions shall have the same argument and if they
            return numpy arrays, the returned arrays shall have the same shape.
        weights: Coefficients of the functions in the linear combination. The i-th given function will be multiplied
            with weights[i].

    Todo:
        Doesn't it better to accept functions as a Collection explicitly?

    Returns:
        A function which returns the linear combination of the given functions output.
    """
    if weights is None:
        weights = np.ones(shape=(len(functions)))
    else:
        assert len(functions) == len(weights), 'the length of weights must be the ' \
                                               'same as the number of given functions'

    def linear_combination(*args, **kwargs):
        return sum((weights[i]*functions[i](*args, **kwargs) for i in range(len(weights))))

    return linear_combination


def make_product(*functions: Callable, exponents: Optional[Sequence] = None) -> Callable: