Resolve "Implement basic structure for the hexagon experiment"

Closes #94 (closed)

• New Hexagon class for hexagon simulations
• A few associated unit tests

lisainstrument/hexagon.py

@@ -14,12 +14,15 @@ Authors:
     Jean-Baptiste Bayle <j2b.bayle@gmail.com>
 """
 
+import logging
 import numpy as np
 
 from h5py import File
 
 from . import noises
 
+logger = logging.getLogger(__name__)
+
 
 class Hexagon():
     """Represent the Hexagon instrument.
@@ -52,12 +55,15 @@ class Hexagon():
         self.duration = self.size * self.dt
         self.time = np.arange(self.size) * self.dt
 
+        logger.info("Initialize hexagon experiment (size=%d, dt=%f, duration=%f",
+            self.size, self.dt, self.duration)
 
         self.primary_laser_asd = float(primary_laser_asd)
         self.locked_laser_asd = float(locked_laser_asd)
 
         self.central_freq = float(central_freq)
         if offset_freqs == 'default':
+            logger.debug("Use default set of offset frequencies")
             self.offset_freqs = {'1': 0.0, '2': 15E6, '3': 7E6}
         else:
             self.offset_freqs = offset_freqs
@@ -76,9 +82,13 @@ class Hexagon():
     def simulate(self):
         """Run a simulation, and generate all intermediary signals."""
 
+        logger.info("Starting simulation")
+        if self.simulated:
+            logger.warning("Overwriting previous simulated values")
 
+        # Laser noise
+        logger.debug("Generating laser noise")
         self.laser_noises = np.empty((self.size, 3)) # (size, laser) [Hz]
-
         # Laser 1 has its own stability
         self.laser_noises[:, 0] = noises.laser(self.fs, self.size, self.primary_laser_asd)
         # Laser 2 replicated laser 1 with added locking noise
@@ -89,6 +99,7 @@ class Hexagon():
             + noises.white(self.fs, self.size, self.locked_laser_asd)
 
         # Carrier beams
+        logger.debug("Simulating carrier beams")
         self.carrier_fluctuations = self.laser_noises # (size, laser) [Hz]
         self.carrier_offsets = np.array(
             [[self.offset_freqs[index] for index in self.INDICES]]
@@ -96,6 +107,7 @@ class Hexagon():
 
         # Compute beatnotes
         # Convention is from paper: beatnote ij is beam j - beam i
+        logger.debug("Computing carrier beatnotes")
         self.carrier_beatnote_offsets = np.stack([
             self.carrier_offsets[:, int(ij[1]) - 1] - self.carrier_offsets[:, int(ij[0]) - 1]
             for ij in self.BEATNOTES
@@ -107,9 +119,11 @@ class Hexagon():
         self.carrier_beatnotes = self.carrier_beatnote_offsets + self.carrier_beatnote_fluctuations
 
         # Three-signal combination
+        logger.debug("Forming three-signal combination")
         self.three_signal_combination = self.carrier_beatnotes[:,0] \
             + self.carrier_beatnotes[:,1] + self.carrier_beatnotes[:,2]
 
+        logger.info("Simulation complete")
         self.simulated = True
 
     def write(self, output='measurements.h5', mode='w'):