from fast_hadamard_transform import hadamard_transform

def hadamard_transform(x, scale=1.0):
    """
    Arguments:
        x: (..., dim)
        scale: float. Multiply the output by this number.
    Returns:
        out: (..., dim)
    Multiply each row of x by the Hadamard transform matrix.
    Equivalent to F.linear(x, torch.tensor(scipy.linalg.hadamard(dim))) * scale.
    If dim is not a power of 2, we implicitly pad x with zero so that dim is the next power of 2.
    """