Simulation: add utils

simulations/lib/__init__.py

@@ -1,2 +1,3 @@
 from .travelsignal import *
 from .location import *
+from .util import *

simulations/lib/location.py

@@ -77,6 +77,9 @@ class Emitter(Location):
     """
     Emit a signal from position x_0 (and time t_0)
     """
+    def __repr__(self):
+        return "Emitter({})".format(repr(self.x))
+
     def emit(self, travel_signal: TravelSignal) -> TravelSignal:
         return partial(travel_signal, x_0=self.x)
 

simulations/lib/util.py

@@ -0,0 +1,20 @@
+"""
+Various useful utilities (duh)
+"""
+
+import numpy as np
+
+def sampled_time(sample_rate=1, start=0, end=1, offset=0):
+    return offset + np.arange(start, end, 1/sample_rate)
+
+def rot_vector(phi1=0.12345):
+    """
+    Return a unit vector rotated by phi radians.
+    """
+
+    unit = np.array([
+                phi1,
+                phi1 - np.pi/2
+            ])
+
+    return np.cos(unit)