def update_lr()

in src/trainer.py [0:0]

• 18 lines of code
• 8 McCabe index (conditional complexity)

    def update_lr(self, to_log, metric):
        """
        Update learning rate when using SGD.
        """
        if 'sgd' not in self.params.map_optimizer:
            return
        old_lr = self.map_optimizer.param_groups[0]['lr']
        new_lr = max(self.params.min_lr, old_lr * self.params.lr_decay)
        if new_lr < old_lr:
            logger.info("Decreasing learning rate: %.8f -> %.8f" % (old_lr, new_lr))
            self.map_optimizer.param_groups[0]['lr'] = new_lr

        if self.params.lr_shrink < 1 and to_log[metric] >= -1e7:
            if to_log[metric] < self.best_valid_metric:
                logger.info("Validation metric is smaller than the best: %.5f vs %.5f"
                            % (to_log[metric], self.best_valid_metric))
                # decrease the learning rate, only if this is the
                # second time the validation metric decreases
                if self.decrease_lr:
                    old_lr = self.map_optimizer.param_groups[0]['lr']
                    self.map_optimizer.param_groups[0]['lr'] *= self.params.lr_shrink
                    logger.info("Shrinking the learning rate: %.5f -> %.5f"
                                % (old_lr, self.map_optimizer.param_groups[0]['lr']))
                self.decrease_lr = True