Merge pull request #240 from nasa/bug/pf_ordering

fixing bug: array and keys did not match in particle_filter

src/prog_algs/state_estimators/particle_filter.py

@@ -67,9 +67,9 @@ def __init__(self, model, x0, **kwargs):
                 # Added to avoid float/int issues
                 self.parameters['num_particles'] = int(self.parameters['num_particles'])
             sample_gen = x0.sample(self.parameters['num_particles'])
-        samples = [array(sample_gen.key(k), dtype=float64) for k in x0.keys()]
+        samples = {k: array(sample_gen.key(k), dtype=float64) for k in x0.keys()}
 
-        self.particles = model.StateContainer(array(samples, dtype=float64))
+        self.particles = model.StateContainer(samples)
 
         if 'R' in self.parameters:
             # For backwards compatibility

tests/test_state_estimators.py

@@ -4,7 +4,7 @@
 import random
 
 from prog_models import PrognosticsModel, LinearModel
-from prog_models.models import ThrownObject, BatteryElectroChem, PneumaticValveBase
+from prog_models.models import ThrownObject, BatteryElectroChem, PneumaticValveBase, BatteryElectroChemEOD
 from prog_algs.state_estimators import ParticleFilter, KalmanFilter, UnscentedKalmanFilter
 from prog_algs.uncertain_data import ScalarData, MultivariateNormalDist, UnweightedSamples
 
@@ -557,6 +557,21 @@ def future_loading(t, x=None):
         times = simulation_result.times
         for t, u, z in zip(times, inputs.data, outputs.data):
             kf.estimate(t, u, z)
+
+    def test_PF_particle_ordering(self):
+        """
+        This is testing for a bug found by @mstraut where particle filter was mixing up the keys if users:
+          1. Do not call m.initialize(), and instead
+          2. provide a state as a dictionary instead of a state container, and
+          3. order the states in a different order than m.states
+        """
+        m = BatteryElectroChemEOD()
+        x0 = m.parameters['x0']  # state as a dictionary with the wrong order
+        filt = ParticleFilter(m, x0, num_particles=2)
+        for key in m.states:
+            self.assertEqual(filt.particles[key][0], x0[key])
+            self.assertEqual(filt.particles[key][1], x0[key])
+
 
 # This allows the module to be executed directly    
 def run_tests():