address review comments

python/gtsam/examples/ImuFactorExample.py

@@ -31,9 +31,28 @@ BIAS_KEY = B(0)
 np.set_printoptions(precision=3, suppress=True)
 
 
+def parse_args():
+    """Parse command line arguments."""
+    parser = argparse.ArgumentParser("ImuFactorExample.py")
+    parser.add_argument("--twist_scenario",
+                        default="sick_twist",
+                        choices=("zero_twist", "forward_twist", "loop_twist",
+                                 "sick_twist"))
+    parser.add_argument("--time",
+                        "-T",
+                        default=12,
+                        type=int,
+                        help="Total time in seconds")
+    parser.add_argument("--compute_covariances",
+                        default=False,
+                        action='store_true')
+    parser.add_argument("--verbose", default=False, action='store_true')
+    args = parser.parse_args()
+
+
 class ImuFactorExample(PreintegrationExample):
     """Class to run example of the Imu Factor."""
-    def __init__(self, twist_scenario="sick_twist"):
+    def __init__(self, twist_scenario: str = "sick_twist"):
         self.velocity = np.array([2, 0, 0])
         self.priorNoise = gtsam.noiseModel.Isotropic.Sigma(6, 0.1)
         self.velNoise = gtsam.noiseModel.Isotropic.Sigma(3, 0.1)
@@ -65,7 +84,7 @@ class ImuFactorExample(PreintegrationExample):
         super(ImuFactorExample, self).__init__(twist_scenarios[twist_scenario],
                                                bias, params, dt)
 
-    def addPrior(self, i, graph):
+    def addPrior(self, i: int, graph: gtsam.NonlinearFactorGraph):
         """Add a prior on the navigation state at time `i`."""
         state = self.scenario.navState(i)
         graph.push_back(
@@ -73,7 +92,8 @@ class ImuFactorExample(PreintegrationExample):
         graph.push_back(
             gtsam.PriorFactorVector(V(i), state.velocity(), self.velNoise))
 
-    def optimize(self, graph, initial):
+    def optimize(self, graph: gtsam.NonlinearFactorGraph,
+                 initial: gtsam.Values):
         """Optimize using Levenberg-Marquardt optimization."""
         params = gtsam.LevenbergMarquardtParams()
         params.setVerbosityLM("SUMMARY")
@@ -82,10 +102,10 @@ class ImuFactorExample(PreintegrationExample):
         return result
 
     def plot(self,
-             values,
+             values: gtsam.Values,
-             title="Estimated Trajectory",
+             title: str = "Estimated Trajectory",
-             fignum=POSES_FIG + 1,
+             fignum: int = POSES_FIG + 1,
-             show=False):
+             show: bool = False):
         """Plot poses in values."""
         i = 0
         while values.exists(X(i)):
@@ -103,7 +123,10 @@ class ImuFactorExample(PreintegrationExample):
         if show:
             plt.show()
 
-    def run(self, T=12, compute_covariances=False, verbose=True):
+    def run(self,
+            T: int = 12,
+            compute_covariances: bool = False,
+            verbose: bool = True):
         """Main runner."""
         graph = gtsam.NonlinearFactorGraph()
 
@@ -193,21 +216,7 @@ class ImuFactorExample(PreintegrationExample):
 
 
 if __name__ == '__main__':
-    parser = argparse.ArgumentParser("ImuFactorExample.py")
+    args = parse_args()
-    parser.add_argument("--twist_scenario",
-                        default="sick_twist",
-                        choices=("zero_twist", "forward_twist", "loop_twist",
-                                 "sick_twist"))
-    parser.add_argument("--time",
-                        "-T",
-                        default=12,
-                        type=int,
-                        help="Total time in seconds")
-    parser.add_argument("--compute_covariances",
-                        default=False,
-                        action='store_true')
-    parser.add_argument("--verbose", default=False, action='store_true')
-    args = parser.parse_args()
 
     ImuFactorExample(args.twist_scenario).run(args.time,
                                               args.compute_covariances,

python/gtsam/examples/PreintegrationExample.py

@@ -12,7 +12,7 @@ Authors: Frank Dellaert, Varun Agrawal.
 
 # pylint: disable=invalid-name,unused-import,wrong-import-order
 
-import math
+from typing import Sequence
 
 import gtsam
 import matplotlib.pyplot as plt
@@ -24,13 +24,13 @@ IMU_FIG = 1
 POSES_FIG = 2
 
 
-class PreintegrationExample(object):
+class PreintegrationExample:
     """Base class for all preintegration examples."""
     @staticmethod
-    def defaultParams(g):
+    def defaultParams(g: float):
         """Create default parameters with Z *up* and realistic noise parameters"""
         params = gtsam.PreintegrationParams.MakeSharedU(g)
-        kGyroSigma = math.radians(0.5) / 60  # 0.5 degree ARW
+        kGyroSigma = np.radians(0.5) / 60  # 0.5 degree ARW
         kAccelSigma = 0.1 / 60  # 10 cm VRW
         params.setGyroscopeCovariance(kGyroSigma**2 * np.identity(3, float))
         params.setAccelerometerCovariance(kAccelSigma**2 *
@@ -38,7 +38,11 @@ class PreintegrationExample(object):
         params.setIntegrationCovariance(0.0000001**2 * np.identity(3, float))
         return params
 
-    def __init__(self, twist=None, bias=None, params=None, dt=1e-2):
+    def __init__(self,
+                 twist: np.ndarray = None,
+                 bias: gtsam.imuBias.ConstantBias = None,
+                 params: gtsam.PreintegrationParams = None,
+                 dt: float = 1e-2):
         """Initialize with given twist, a pair(angularVelocityVector, velocityVector)."""
 
         # setup interactive plotting
@@ -50,7 +54,7 @@ class PreintegrationExample(object):
         else:
             # default = loop with forward velocity 2m/s, while pitching up
             # with angular velocity 30 degree/sec (negative in FLU)
-            W = np.array([0, -math.radians(30), 0])
+            W = np.array([0, -np.radians(30), 0])
             V = np.array([2, 0, 0])
 
         self.scenario = gtsam.ConstantTwistScenario(W, V)
@@ -80,7 +84,8 @@ class PreintegrationExample(object):
         fig, self.axes = plt.subplots(4, 3)
         fig.set_tight_layout(True)
 
-    def plotImu(self, t, measuredOmega, measuredAcc):
+    def plotImu(self, t: float, measuredOmega: Sequence,
+                measuredAcc: Sequence):
         """Plot IMU measurements."""
         plt.figure(IMU_FIG)
 
@@ -114,12 +119,15 @@ class PreintegrationExample(object):
             ax.scatter(t, measuredAcc[i], color=color, marker='.')
             ax.set_xlabel('specific force ' + label)
 
-    def plotGroundTruthPose(self, t, scale=0.3, time_interval=0.01):
+    def plotGroundTruthPose(self,
+                            t: float,
+                            scale: float = 0.3,
+                            time_interval: float = 0.01):
         """Plot ground truth pose, as well as prediction from integrated IMU measurements."""
         actualPose = self.scenario.pose(t)
         plot_pose3(POSES_FIG, actualPose, scale)
-        t = actualPose.translation()
+        translation = actualPose.translation()
-        self.maxDim = max([max(np.abs(t)), self.maxDim])
+        self.maxDim = max([max(np.abs(translation)), self.maxDim])
         ax = plt.gca()
         ax.set_xlim3d(-self.maxDim, self.maxDim)
         ax.set_ylim3d(-self.maxDim, self.maxDim)
@@ -127,7 +135,7 @@ class PreintegrationExample(object):
 
         plt.pause(time_interval)
 
-    def run(self, T=12):
+    def run(self, T: int = 12):
         """Simulate the loop."""
         for i, t in enumerate(np.arange(0, T, self.dt)):
             measuredOmega = self.runner.measuredAngularVelocity(t)