Method backward

imperative/python/src/grad.cpp:50–64

}

void GradKeyWrapper::backward(GradKeyWrapper* self, py::list tensors, py::list grads) {
    std::vector<ValueRef> args;
    mgb_assert(tensors.size() == grads.size());
    for (auto&& tensor : tensors) {
        auto* tw = TensorWrapper::try_cast(tensor.ptr());
        mgb_assert(tw, "expect Tensor");
        args.push_back(tw->m_tensor->data());
    }
    for (auto&& grad : grads) {
        auto* tw = TensorWrapper::try_cast(grad.ptr());
        mgb_assert(tw, "expect Tensor");
        args.push_back(tw->m_tensor->data());
    }
    imperative::apply(GradBackward(self->m_key), {args.data(), args.size()});
}

pybind11::function GradKeyWrapper::get_backward_closure(
        GradKeyWrapper* self, py::list tensors) {