add ARS to train/eval Minitaur

examples/pybullet/gym/pybullet_envs/ARS/train_ars.py

@@ -0,0 +1,64 @@
+"""TODO(jietan): DO NOT SUBMIT without one-line documentation for train_ars.
+
+blaze build -c opt //experimental/users/jietan/ARS:train_ars
+blaze-bin/experimental/users/jietan/ARS/train_ars \
+--logdir=/cns/ij-d/home/jietan/experiment/ARS/test1 \
+--config_name=MINITAUR_GYM_CONFIG
+"""
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+import os
+from absl import app
+from absl import flags
+import ars
+import config_ars
+
+FLAGS = flags.FLAGS
+flags.DEFINE_string('logdir', None, 'The directory to write the log file.')
+flags.DEFINE_string('config_name', None, 'The name of the config dictionary')
+
+
+def run_ars(config, logdir):
+
+  env = config["env"]()
+  ob_dim = env.observation_space.shape[0]
+  ac_dim = env.action_space.shape[0]
+
+  # set policy parameters. Possible filters: 'MeanStdFilter' for v2, 'NoFilter' for v1.
+  policy_params = {
+      'type': 'linear',
+      'ob_filter': config['filter'],
+      'ob_dim': ob_dim,
+      'ac_dim': ac_dim
+  }
+
+  ARS = ars.ARSLearner(
+      env_callback=config['env'],
+      policy_params=policy_params,
+      num_deltas=config['num_directions'],
+      deltas_used=config['deltas_used'],
+      step_size=config['step_size'],
+      delta_std=config['delta_std'],
+      logdir=logdir,
+      rollout_length=config['rollout_length'],
+      shift=config['shift'],
+      params=config,
+      seed=config['seed'])
+
+  return ARS.train(config['num_iterations'])
+
+
+def main(argv):
+  del argv  # Unused.
+  config = getattr(config_ars, FLAGS.config_name)
+  run_ars(config=config, logdir=FLAGS.logdir)
+
+
+if __name__ == '__main__':
+  flags.mark_flag_as_required('logdir')
+  flags.mark_flag_as_required('config_name')
+  app.run(main)