Fix pitch_r2 not working

Author: yqzhishen

training/variance_task.py

@@ -281,6 +281,7 @@ def sample_get(key, idx, abs_idx):
                         gt_pitch = sample_get('pitch', i, data_idx)
                         mask = (sample_get('mel2ph', i, data_idx) > 0) & ~sample_get('uv', i, data_idx)
                         self.valid_metrics['pitch_acc'].update(pred=pred_pitch, target=gt_pitch, mask=mask)
+                        self.valid_metrics['pitch_r2'].update(pred=pred_pitch, target=gt_pitch, mask=mask)
                         self.plot_pitch(
                             data_idx,
                             gt_pitch=gt_pitch,