Policy Service complete

src/active_bo_msgs/CMakeLists.txt

@@ -17,18 +17,14 @@ endif()
 
 # find dependencies
 find_package(ament_cmake REQUIRED)
-# uncomment the following section in order to fill in
+find_package(rosidl_default_generators REQUIRED)
-# further dependencies manually.
+
-# find_package(<dependency> REQUIRED)
+rosidl_generate_interfaces(${PROJECT_NAME}
+    "srv/WeightToPolicy.srv"
+)
 
 if(BUILD_TESTING)
   find_package(ament_lint_auto REQUIRED)
-  # the following line skips the linter which checks for copyrights
-  # uncomment the line when a copyright and license is not present in all source files
-  #set(ament_cmake_copyright_FOUND TRUE)
-  # the following line skips cpplint (only works in a git repo)
-  # uncomment the line when this package is not in a git repo
-  #set(ament_cmake_cpplint_FOUND TRUE)
   ament_lint_auto_find_test_dependencies()
 endif()
 

src/active_bo_msgs/package.xml

@@ -9,6 +9,12 @@
 
   <buildtool_depend>ament_cmake</buildtool_depend>
 
+  <build_depend>rosidl_default_generators</build_depend>
+
+  <exec_depend>rosidl_default_runtime</exec_depend>
+
+  <member_of_group>rosidl_interface_packages</member_of_group>
+
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
 

src/active_bo_msgs/srv/WeightToPolicy.srv

@@ -0,0 +1,4 @@
+float32[] weights
+uint16 nr_steps
+---
+float32[] policy

src/active_bo_ros/active_bo_ros/AcquisitionFunctions/ConfidenceBound.py

@@ -0,0 +1,13 @@
+import numpy as np
+
+def ConfidenceBound(gp, X, nr_test, nr_weights, lam=1.2, seed=None, lower=-1.0, upper=1.0):
+    y_hat = gp.predict(X)
+    best_y = max(y_hat)
+    rng = np.random.default_rng(seed=seed)
+    X_test = rng.uniform(lower, upper, (nr_test, nr_weights))
+    mu, sigma = gp.predict(X_test, return_std=True)
+    cb = mu + lam * sigma
+
+    idx = np.argmax(cb)
+    X_next = X_test[idx, :]
+    return X_next

src/active_bo_ros/active_bo_ros/AcquisitionFunctions/ExpectedImprovement.py

@@ -0,0 +1,15 @@
+import numpy as np
+from scipy.stats import norm
+
+def ExpectedImprovement(gp, X, nr_test, nr_weights, kappa=2.576, seed=None, lower=-1.0, upper=1.0):
+    y_hat = gp.predict(X)
+    best_y = max(y_hat)
+    rng = np.random.default_rng(seed=seed)
+    X_test = rng.uniform(lower, upper, (nr_test, nr_weights))
+    mu, sigma = gp.predict(X_test, return_std=True)
+    z = (mu - best_y - kappa) / sigma
+    ei = (mu - best_y - kappa) * norm.cdf(z) + sigma * norm.pdf(z)
+
+    idx = np.argmax(ei)
+    X_next = X_test[idx, :]
+    return X_next

src/active_bo_ros/active_bo_ros/AcquisitionFunctions/ProbabilityOfImprovement.py

@@ -0,0 +1,15 @@
+import numpy as np
+from scipy.stats import norm
+
+def ProbabilityOfImprovement(gp, X, nr_test, nr_weights, kappa=2.576, seed=None, lower=-1.0, upper=1.0):
+    y_hat = gp.predict(X)
+    best_y = max(y_hat)
+    rng = np.random.default_rng(seed=seed)
+    X_test = rng.uniform(lower, upper, (nr_test, nr_weights))
+    mu, sigma = gp.predict(X_test, return_std=True)
+    z = (mu - best_y - kappa) / sigma
+    pi = norm.cdf(z)
+
+    idx = np.argmax(pi)
+    X_next = X_test[idx, :]
+    return X_next

src/active_bo_ros/active_bo_ros/PolicyModel/GaussianRBFModel.py

@@ -0,0 +1,53 @@
+import numpy as np
+class GaussianRBF:
+    def __init__(self, nr_weights, nr_steps, seed=None, lowerb=-1.0, upperb=1.0):
+        self.nr_weights = nr_weights
+        self.nr_steps = nr_steps
+        self.weights = None
+        self.policy = None
+        self.mean = np.linspace(0, self.nr_steps, self.nr_weights)
+        if nr_weights > 1:
+            self.std = self.mean[1] / (2 * np.sqrt(2 * np.log(2)))  # Full width at half maximum
+        else:
+            self.std = self.nr_steps / 2
+
+        self.rng = np.random.default_rng(seed=seed)
+        self.low = lowerb
+        self.upper = upperb
+
+        self.reset()
+
+    def reset(self):
+        self.weights = np.zeros((self.nr_weights, 1))
+        self.policy = np.zeros((self.nr_steps, 1))
+
+    def random_policy(self):
+        self.weights = self.rng.uniform(self.low, self.upper, self.nr_weights)
+
+    def policy_rollout(self):
+        self.policy = np.zeros((self.nr_steps, 1))
+        for i in range(self.nr_steps):
+            for j in range(self.nr_weights):
+                base_fun = np.exp(-0.5*(i - self.mean[j])**2 / self.std**2)
+                self.policy[i] += base_fun * self.weights[j]
+
+        return self.policy
+
+    # def plot_policy(self, finished=np.NAN):
+    #     x = np.linspace(0, self.nr_steps, self.nr_steps)
+    #     plt.plot(x, self.trajectory)
+    #     if finished != np.NAN:
+    #         plt.vlines(finished, -1, 1, colors='red')
+    #     # for i in self.mean:
+    #     #     gaussian = np.exp(-0.5 * (x - i)**2 / self.std**2)
+    #     #     plt.plot(x, gaussian)
+
+
+def main():
+    policy = GaussianRBFModel(1, 50)
+    policy.random_policy()
+    policy.policy_rollout()
+    print(policy.weights)
+
+if __name__ == "__main__":
+    main()

src/active_bo_ros/active_bo_ros/policy_service.py

@@ -0,0 +1,37 @@
+from active_bo_msgs.srv import WeightToPolicy
+
+import rclpy
+from rclpy.node import Node
+
+from active_bo_ros.PolicyModel.GaussianRBFModel import GaussianRBF
+import numpy as np
+
+class PolicyService(Node):
+    def __init__(self):
+        super().__init__('policy_service')
+        self.srv = self.create_service(WeightToPolicy, 'policy_srv', self.policy_callback)
+
+    @staticmethod
+    def policy_callback(request, response):
+        weights = request.weights
+        weight_len = len(weights)
+        nr_steps = request.nr_steps
+
+        policy = GaussianRBF(weight_len, nr_steps)
+        policy.weights = weights
+        policy.policy_rollout()
+
+        response.policy = policy.policy.flatten().tolist()
+        return response
+
+def main(args=None):
+    rclpy.init(args=args)
+
+    policy_service = PolicyService()
+
+    rclpy.spin(policy_service)
+
+    rclpy.shutdown()
+
+if __name__ == "__main__":
+    main()

src/active_bo_ros/launch/policy_service.launch.py

@@ -0,0 +1,11 @@
+from launch import LaunchDescription
+from launch_ros.actions import Node
+
+def generate_launch_description():
+    return LaunchDescription([
+        Node(
+            package='active_bo_ros',
+            executable='policy_srv',
+            name='policy_srv'
+        ),
+    ])

src/active_bo_ros/package.xml

@@ -7,6 +7,10 @@
   <maintainer email="nikolaus.feith@unileoben.ac.at">cpsfeith</maintainer>
   <license>TODO: License declaration</license>
 
+  <exec_depend>example_interfaces</exec_depend>
+  <exec_depend>active_bo_msgs</exec_depend>
+  <exec_depend>rclpy</exec_depend>
+
   <test_depend>ament_copyright</test_depend>
   <test_depend>ament_flake8</test_depend>
   <test_depend>ament_pep257</test_depend>

src/active_bo_ros/setup.py

@@ -1,17 +1,20 @@
 from setuptools import setup
+import os
+from glob import glob
 
 package_name = 'active_bo_ros'
 
 setup(
     name=package_name,
     version='0.0.0',
-    packages=[package_name],
+    packages=[package_name, package_name+'/PolicyModel'],
     data_files=[
         ('share/ament_index/resource_index/packages',
             ['resource/' + package_name]),
         ('share/' + package_name, ['package.xml']),
+        (os.path.join('share', package_name), glob('launch/*.launch.py')),
     ],
-    install_requires=['setuptools'],
+    install_requires=['setuptools', 'numpy'],
     zip_safe=True,
     maintainer='cpsfeith',
     maintainer_email='nikolaus.feith@unileoben.ac.at',
@@ -20,6 +23,7 @@ setup(
     tests_require=['pytest'],
     entry_points={
         'console_scripts': [
+            'policy_srv = active_bo_ros.policy_service:main'
         ],
     },
 )