Function test_backward

tests/python/common/test_heterograph.py:2048–2073

(idtype)

@parametrize_idtype
def test_backward(idtype):
    g = create_test_heterograph(idtype)
    x = F.randn((3, 5))
    F.attach_grad(x)
    g.nodes["user"].data["h"] = x
    with F.record_grad():
        g.multi_update_all(
            {
                "plays": (fn.copy_u("h", "m"), fn.sum("m", "y")),
                "wishes": (fn.copy_u("h", "m"), fn.sum("m", "y")),
            },
            "sum",
        )
        y = g.nodes["game"].data["y"]
        F.backward(y, F.ones(y.shape))
    print(F.grad(x))
    assert F.array_equal(
        F.grad(x),
        F.tensor(
            [
                [2.0, 2.0, 2.0, 2.0, 2.0],
                [2.0, 2.0, 2.0, 2.0, 2.0],
                [2.0, 2.0, 2.0, 2.0, 2.0],
            ]
        ),
    )


@parametrize_idtype