Method backward

model/functional/toeplitz.py:108–112

(ctx, grad)

    @staticmethod
    def backward(ctx, grad):
        u, v = ctx.saved_tensors
        d_u = triangular_toeplitz_multiply_padded_(grad.flip(-1), v).flip(-1)
        d_v = triangular_toeplitz_multiply_padded_(grad.flip(-1), u).flip(-1)
        return d_u, d_v

class TriangularToeplitzMultPaddedFast(torch.autograd.Function):
    """ Trade off speed (20-25% faster) for more memory (20-25%) """