function_tools.py 文件源码

def outer_product(input_array):
    r'''
    Takes a `NumPy` array and returns the outer (dyadic, Kronecker) product
    with itself. If `input_array` is a vector :math:`\mathbf{x}`, this returns
    :math:`\mathbf{x}\mathbf{x}^T`.
    '''
    la = len(input_array)

    # return outer product as numpy array
    return np.kron(input_array, input_array).reshape(la, la)

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# Decorators #
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# Main decorator for fit functions