Fix train_stats.pdf: they now work by default

Summary: Before this diff, train_stats.py would not be created by default, EXCEPT when resuming training. This makes them appear from start.

Reviewed By: shapovalov

Differential Revision: D38320341

fbshipit-source-id: 8ea5b99ec81c377ae129f58e78dc2eaff94821ad

projects/implicitron_trainer/impl/model_factory.py

@@ -159,6 +159,7 @@ class ImplicitronModelFactory(ModelFactoryBase):  # pyre-ignore [13]
         stats = Stats(
             # log_vars should be a list, but OmegaConf might load them as ListConfig
             list(log_vars),
+            plot_file=os.path.join(exp_dir, "train_stats.pdf"),
             visdom_env=visdom_env_charts,
             verbose=False,
             visdom_server=self.visdom_server,