Update to platform to allow it to control the positions of its sensors (

#177)

Update to platform to allow it to control the positions of its sensors, rather than saving it to the sensor each time the platform moves.

- Create both fixed and moving sensor platforms
- Force a sensor to be mounted to a platform
- Give sensors a default fixed platform if position and or/orientation are specified
- properties for position, velocity and orientation
- Use mappings between state_vector and position/velocity
- Give Platform a state_vector/timestamp property
- Update tests to match

docs/source/stonesoup.sensor.rst

@@ -10,6 +10,9 @@ Sensors
 .. automodule:: stonesoup.sensor.base
     :show-inheritance:
 
+.. automodule:: stonesoup.sensor.sensor
+    :show-inheritance:
+
 
 Passive
 -------

stonesoup/models/measurement/base.py

@@ -1,18 +1,17 @@
 # -*- coding: utf-8 -*-
-from abc import abstractmethod
+from abc import abstractmethod, ABC
 
-import scipy as sp
+import numpy as np
 
 from ..base import Model
 from ...base import Property
 
 
-class MeasurementModel(Model):
+class MeasurementModel(Model, ABC):
     """Measurement Model base class"""
 
     ndim_state = Property(int, doc="Number of state dimensions")
-    mapping = Property(
-        sp.ndarray, doc="Mapping between measurement and state dims")
+    mapping = Property(np.ndarray, doc="Mapping between measurement and state dims")
 
     @property
     def ndim(self):

stonesoup/models/measurement/nonlinear.py

@@ -1,4 +1,6 @@
 # -*- coding: utf-8 -*-
+from abc import ABC
+from typing import List
 import copy
 
 import numpy as np
@@ -15,8 +17,7 @@
 from .base import MeasurementModel
 
 
-class CombinedReversibleGaussianMeasurementModel(
-        ReversibleModel, GaussianModel, MeasurementModel):
+class CombinedReversibleGaussianMeasurementModel(ReversibleModel, GaussianModel, MeasurementModel):
     r"""Combine multiple models into a single model by stacking them.
 
     The assumption is that all models are Gaussian, and must be combination of
@@ -29,8 +30,7 @@ class CombinedReversibleGaussianMeasurementModel(
     :class:`~.LinearModel` or :class:`~.ReversibleModel`.
     """
     mapping = None
-    model_list = Property(
-        [MeasurementModel], doc="List of Measurement Models.")
+    model_list = Property(List[MeasurementModel], doc="List of Measurement Models.")
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -90,9 +90,7 @@ def rvs(self, num_samples=1, **kwargs):
             return rvs_vectors.view(Matrix)
 
 
-class NonLinearGaussianMeasurement(MeasurementModel,
-                                   NonLinearModel,
-                                   GaussianModel):
+class NonLinearGaussianMeasurement(MeasurementModel, NonLinearModel, GaussianModel, ABC):
     r"""This class combines the MeasurementModel, NonLinearModel and \
     GaussianModel classes. It is not meant to be instantiated directly \
     but subclasses should be derived from this class.
@@ -272,8 +270,7 @@ def rvs(self, num_samples=1, **kwargs):
         return out
 
 
-class CartesianToBearingRange(
-        NonLinearGaussianMeasurement, ReversibleModel):
+class CartesianToBearingRange(NonLinearGaussianMeasurement, ReversibleModel):
     r"""This is a class implementation of a time-invariant measurement model, \
     where measurements are assumed to be received in the form of bearing \
     (:math:`\phi`) and range (:math:`r`), with Gaussian noise in each dimension.