chainer.force_backprop_mode

chainer.force_backprop_mode()

Make a context manager which enables back-propagation.

When you want to enable back-propagation in no_backprop_mode(), call this method. :~chainer.Variable: created in this context always has a computational graph. If you call this method outside of no_backprop_mode() context, it changes nothing.

In this example, y has a computational graph and y.backward computes gradients of variables in the graph.

>>> with chainer.no_backprop_mode():
...   with chainer.force_backprop_mode():
...     y = x + 1

See also

See no_backprop_mode() for details of back-prop mode.