Added defense agent example.

example/defense_1v1.sh

+#!/bin/bash
+
+./bin/HFO --offense-npcs=1 --defense-agents=1 --trials 20 --agent-play-goalie --headless &
+sleep 5
+./example/example_defense_agent.py &> agent1.txt &
+sleep 5
+
+# The magic line
+#   $$ holds the PID for this script
+#   Negation means kill by process group id instead of PID
+trap "kill -TERM -$$" SIGINT
+wait
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example/example_defense_agent.py

+#!/usr/bin/env python
+# encoding: utf-8
+
+# Before running this program, first Start HFO server:
+# $> ./bin/HFO --offense-agents 1
+
+import itertools
+from hfo import *
+
+def main():
+  # Create the HFO Environment
+  hfo = HFOEnvironment()
+  # Connect to the server with the specified
+  # feature set. See feature sets in hfo.py/hfo.hpp.
+  hfo.connectToServer(LOW_LEVEL_FEATURE_SET,
+                      'bin/teams/base/config/formations-dt', 6000,
+                      'localhost', 'base_right', True)
+  for episode in itertools.count():
+    status = IN_GAME
+    while status == IN_GAME:
+      # Grab the state features from the environment
+      features = hfo.getState()
+      # Take an action and get the current game status
+      hfo.act(DASH, 20.0, 0.)
+      # Advance the environment and get the game status
+      status = hfo.step()
+    # Check the outcome of the episode
+    print(('Episode %d ended with %s'%(episode, hfo.statusToString(status))))
+    # Quit if the server goes down
+    if status == SERVER_DOWN:
+      hfo.act(QUIT)
+      break
+
+if __name__ == '__main__':
+  main()
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