Metric can accept a dictionary

[vfdev-5]

Idea is to simplify user code and add logic into Metric to accept engine's output as

output = {'y_pred': y_pred, 'y': y, ...}

Such that Metric can work on the output of the following formats:

• (y_pred, y)
• {'y_pred': y_pred, 'y': y, ...}

This could help to avoid writing output_transform adaptor.

[vfdev-5]

I thought about automatically prepare output = {'y_pred': y_pred, 'y': y, ...} into output = (y_pred, y) between 118 and 119 if self._output_transform(engine.state.output) outputs a mapping.

ignite/ignite/metrics/metric.py

Lines 117 to 119 in 5a32816

	def iteration_completed(self, engine):
	output = self._output_transform(engine.state.output)
	self.update(output)