From 4011a5c69862a7744ed27adcb5f924e71cd09f8d Mon Sep 17 00:00:00 2001
From: Deepak <dmallubhotla+github@gmail.com>
Date: Sun, 29 Aug 2021 15:38:41 -0500
Subject: [PATCH] Adds better test for static dipole as well as calculating dot
 measurements

---
 pathfinder/model/__init__.py     |  4 ++--
 pathfinder/model/dot.py          |  7 ++-----
 pathfinder/model/staticdipole.py | 33 +++++++++++++++++++++++++++++---
 tests/model/test_staticdipole.py | 23 ++++++++++++++++++++++
 4 files changed, 57 insertions(+), 10 deletions(-)
 create mode 100644 tests/model/test_staticdipole.py

diff --git a/pathfinder/model/__init__.py b/pathfinder/model/__init__.py
index 65ff72d..1425108 100644
--- a/pathfinder/model/__init__.py
+++ b/pathfinder/model/__init__.py
@@ -1,5 +1,5 @@
 from pathfinder.model.dot import DotMeasurement
 from pathfinder.model.model import DotDipoleModel
-from pathfinder.model.staticdipole import StaticDipole
+from pathfinder.model.staticdipole import StaticDipoleArrangement, StaticDipole
 
-__all__ = ['DotMeasurement', 'DotDipoleModel', 'StaticDipole']
+__all__ = ['DotMeasurement', 'DotDipoleModel', 'StaticDipoleArrangement', 'StaticDipole']
diff --git a/pathfinder/model/dot.py b/pathfinder/model/dot.py
index a59b23d..b8f0b3e 100644
--- a/pathfinder/model/dot.py
+++ b/pathfinder/model/dot.py
@@ -2,8 +2,6 @@ from dataclasses import dataclass
 import numpy
 import numpy.typing
 
-from pathfinder.model.staticdipole import StaticDipole
-
 
 @dataclass
 class DotMeasurement():
@@ -38,9 +36,8 @@ class DotMeasurement():
 		p = pt[0:3]  # hardcoded here because chances
 		s = pt[3:6]  # are we'll only ever work in 3d.
 
-		dipole = StaticDipole(p, s)
-
-		return dipole.v_at_position(self.r)
+		diff = self.r - s
+		return p.dot(diff) / (numpy.linalg.norm(diff)**3)
 
 	def cost(self, pts: numpy.ndarray) -> float:
 		# 6 because dipole in 3d has 6 degrees of freedom.
diff --git a/pathfinder/model/staticdipole.py b/pathfinder/model/staticdipole.py
index 0e9c09a..14f12be 100644
--- a/pathfinder/model/staticdipole.py
+++ b/pathfinder/model/staticdipole.py
@@ -1,6 +1,8 @@
 from dataclasses import dataclass
 import numpy
 import numpy.typing
+from typing import Sequence, List
+from pathfinder.model.dot import DotMeasurement
 
 
 @dataclass
@@ -20,12 +22,37 @@ class StaticDipole():
 
 	def __post_init__(self) -> None:
 		'''
-			Coerce the inputs into numpy arrays.
+		Coerce the inputs into numpy arrays.
 		'''
 		self.p = numpy.array(self.p)
 		self.s = numpy.array(self.s)
 
-	def v_at_position(self, r: numpy.typing.ArrayLike) -> float:
-
+	def v_at_position(self, r: numpy.ndarray) -> float:
+		'''
+		Mirrors the same function in pathfinder.model.dot.
+		'''
 		diff = r - self.s
 		return self.p.dot(diff) / (numpy.linalg.norm(diff)**3)
+
+
+class StaticDipoleArrangement():
+	'''
+	A collection of static dipoles, which we are interested in being able to characterise.
+
+	Parameters
+	--------
+	dipoles : Sequence[StaticDipole]
+	'''
+	def __init__(self, dipoles):
+		self.dipoles = dipoles
+
+	def get_dot_measurement(self, dot_position: numpy.typing.ArrayLike) -> DotMeasurement:
+		r = numpy.array(dot_position)
+		return DotMeasurement(sum([dipole.v_at_position(r) for dipole in self.dipoles]), r)
+
+	def get_dot_measurements(self, dot_positions: Sequence[numpy.typing.ArrayLike]) -> List[DotMeasurement]:
+		'''
+		For a series of points, each with three coordinates, return
+		'''
+
+		return [self.get_dot_measurement(dot_position) for dot_position in dot_positions]
diff --git a/tests/model/test_staticdipole.py b/tests/model/test_staticdipole.py
new file mode 100644
index 0000000..3ee1298
--- /dev/null
+++ b/tests/model/test_staticdipole.py
@@ -0,0 +1,23 @@
+import numpy
+import pathfinder.model as model
+
+
+def test_static_dipole():
+	d1 = model.StaticDipole((1, 2, 3), (4, 5, 6))
+	d2 = model.StaticDipole((4, 5, 6), (1, 2, 3))
+	dipoles = model.StaticDipoleArrangement([d1, d2])
+
+	dot_position1 = (-1, -1, -1)
+	expected_v1 = -0.3338923121348659
+
+	numpy.testing.assert_allclose(dipoles.get_dot_measurement(dot_position1).v, expected_v1, err_msg="Voltage at dot isn't as expected.")
+	numpy.testing.assert_allclose(dipoles.get_dot_measurement(dot_position1).r, dot_position1, err_msg="Dot isn't where expected.")
+
+	# test multiple dots
+	dot_position2 = (-1, -1, -5)
+	expected_v2 = -0.1254445237566694
+
+	both_measurements = dipoles.get_dot_measurements([dot_position1, dot_position2])
+	measured_voltages = numpy.sort([m.v for m in both_measurements])
+	expected_measured_voltages = numpy.sort([expected_v1, expected_v2])
+	numpy.testing.assert_allclose(measured_voltages, expected_measured_voltages, err_msg="Didn't get the measured voltages expected")