Plot histograms of parameters to tensorboard (facebookresearch#432)

Summary:
Pull Request resolved: facebookresearch#432

- Plot the histogram of weights for every parameter in the model at the end of every train phase.
- Updated the various scalars plotted to Tensorboard to have their own tags, just like "Speed" to organize things better

Adding the activations and gradients is non-trivial since they depend on the input, so skipping that for now.

Reviewed By: vreis

Differential Revision: D20427992

fbshipit-source-id: 148b5e52cb72377c38a6c0a379c669476f9033b2

Author: mannatsingh

classy_vision/hooks/tensorboard_plot_hook.py

@@ -60,6 +60,16 @@ def on_phase_start(self, task: "tasks.ClassyTask") -> None:
         self.wall_times = []
         self.num_steps_global = []
 
+        if not is_master():
+            return
+
+        # log the parameters before training starts
+        if task.train and task.train_phase_idx == 0:
+            for name, parameter in task.base_model.named_parameters():
+                self.tb_writer.add_histogram(
+                    f"Parameters/{name}", parameter, global_step=-1
+                )
+
     def on_step(self, task: "tasks.ClassyTask") -> None:
         """Store the observed learning rates."""
         if self.learning_rates is None:
@@ -92,27 +102,26 @@ def on_phase_end(self, task: "tasks.ClassyTask") -> None:
         logging.info(f"Plotting to Tensorboard for {phase_type} phase {phase_type_idx}")
 
         phase_type = task.phase_type
-        loss_key = f"{phase_type}_loss"
-        learning_rate_key = f"{phase_type}_learning_rate_updates"
+        learning_rate_key = f"Learning Rate/{phase_type}"
 
         if task.train:
-            for loss, learning_rate, global_step, wall_time in zip(
-                task.losses, self.learning_rates, self.num_steps_global, self.wall_times
+            for learning_rate, global_step, wall_time in zip(
+                self.learning_rates, self.num_steps_global, self.wall_times
             ):
-                loss /= task.get_batchsize_per_replica()
-                self.tb_writer.add_scalar(
-                    loss_key, loss, global_step=global_step, walltime=wall_time
-                )
                 self.tb_writer.add_scalar(
                     learning_rate_key,
                     learning_rate,
                     global_step=global_step,
                     walltime=wall_time,
                 )
+            for name, parameter in task.base_model.named_parameters():
+                self.tb_writer.add_histogram(
+                    f"Parameters/{name}", parameter, global_step=phase_type_idx
+                )
 
         loss_avg = sum(task.losses) / (batches * task.get_batchsize_per_replica())
 
-        loss_key = "avg_{phase_type}_loss".format(phase_type=task.phase_type)
+        loss_key = "Losses/{phase_type}".format(phase_type=task.phase_type)
         self.tb_writer.add_scalar(loss_key, loss_avg, global_step=phase_type_idx)
 
         # plot meters which return a dict
@@ -122,13 +131,13 @@ def on_phase_end(self, task: "tasks.ClassyTask") -> None:
                 continue
             for name, value in meter.value.items():
                 if isinstance(value, float):
-                    meter_key = f"{phase_type}_{meter.name}_{name}"
+                    meter_key = f"Meters/{phase_type}/{meter.name}/{name}"
                     self.tb_writer.add_scalar(
                         meter_key, value, global_step=phase_type_idx
                     )
                 else:
                     log.warn(
-                        f"Skipping meter name {meter.name}_{name} with value: {value}"
+                        f"Skipping meter name {meter.name}/{name} with value: {value}"
                     )
                     continue
 

test/manual/hooks_tensorboard_plot_hook_test.py

@@ -93,24 +93,20 @@ def test_writer(self, mock_is_master_func: mock.MagicMock) -> None:
             if master:
                 # add_scalar() should have been called with the right scalars
                 if train:
-                    loss_key = f"{phase_type}_loss"
-                    learning_rate_key = f"{phase_type}_learning_rate_updates"
-                    summary_writer.add_scalar.assert_any_call(
-                        loss_key, mock.ANY, global_step=mock.ANY, walltime=mock.ANY
-                    )
+                    learning_rate_key = f"Learning Rate/{phase_type}"
                     summary_writer.add_scalar.assert_any_call(
                         learning_rate_key,
                         mock.ANY,
                         global_step=mock.ANY,
                         walltime=mock.ANY,
                     )
-                avg_loss_key = f"avg_{phase_type}_loss"
+                avg_loss_key = f"Losses/{phase_type}"
                 summary_writer.add_scalar.assert_any_call(
                     avg_loss_key, mock.ANY, global_step=mock.ANY
                 )
                 for meter in task.meters:
                     for name in meter.value:
-                        meter_key = f"{phase_type}_{meter.name}_{name}"
+                        meter_key = f"Meters/{phase_type}/{meter.name}/{name}"
                         summary_writer.add_scalar.assert_any_call(
                             meter_key, mock.ANY, global_step=mock.ANY
                         )
@@ -134,6 +130,9 @@ def __init__(self):
 
             def add_scalar(self, key, value, global_step=None, walltime=None) -> None:
                 self.scalar_logs[key] = self.scalar_logs.get(key, []) + [value]
+            
+            def add_histogram(self, key, value, global_step=None, walltime=None) -> None:
+                return
 
             def flush(self):
                 return
@@ -154,6 +153,6 @@ def flush(self):
 
         # We have 20 samples, batch size is 10. Each epoch is done in two steps.
         self.assertEqual(
-            writer.scalar_logs["train_learning_rate_updates"],
+            writer.scalar_logs["Learning Rate/train"],
             [0, 1 / 6, 2 / 6, 3 / 6, 4 / 6, 5 / 6],
         )