Cleanup

1 files changed, 36 insertions, 31 deletions

diff --git a/dpd/src/Symbol_align.py b/dpd/src/Symbol_align.py
index e21e793..4ea79c5 100644
--- a/dpd/src/Symbol_align.py
+++ b/dpd/src/Symbol_align.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Modulation Error Rate
+# DPD Calculation Engine, Modulation Error Rate.
 #
 # http://www.opendigitalradio.org
 # Licence: The MIT License, see notice at the end of this file
@@ -8,24 +8,50 @@
 import datetime
 import os
 import logging
-import time
+
 try:
     logging_path = os.path.dirname(logging.getLoggerClass().root.handlers[0].baseFilename)
 except:
     logging_path = "/tmp/"
 
 import numpy as np
-import src.Const
 import scipy
 import matplotlib
+
 matplotlib.use('agg')
 import matplotlib.pyplot as plt
 
+
+def _remove_outliers(x, stds=5):
+    deviation_from_mean = np.abs(x - np.mean(x))
+    inlier_idxs = deviation_from_mean < stds * np.std(x)
+    x = x[inlier_idxs]
+    return x
+
+
+def _calc_delta_angle(fft):
+    # Introduce invariance against carrier
+    angles = np.angle(fft) % (np.pi / 2.)
+
+    # Calculate Angle difference and compensate jumps
+    deltas_angle = np.diff(angles)
+    deltas_angle[deltas_angle > np.pi / 4.] = \
+        deltas_angle[deltas_angle > np.pi / 4.] - np.pi / 2.
+    deltas_angle[-deltas_angle > np.pi / 4.] = \
+        deltas_angle[-deltas_angle > np.pi / 4.] + np.pi / 2.
+    deltas_angle = _remove_outliers(deltas_angle)
+
+    delta_angle = np.mean(deltas_angle)
+
+    return delta_angle
+
+
 class Symbol_align:
     """
     Find the phase offset to the start of the DAB symbols in an
     unaligned dab signal.
     """
+
     def __init__(self, c, plot=False):
         self.c = c
         self.plot = plot
@@ -95,8 +121,8 @@ class Symbol_align:
             ax.set_title("Min Filter")
 
             ax = fig.add_subplot(4, 1, 4)
-            tx_product_crop = tx_product[peaks[0]-50:peaks[0]+50]
-            x = range(tx_product.shape[0])[peaks[0]-50:peaks[0]+50]
+            tx_product_crop = tx_product[peaks[0] - 50:peaks[0] + 50]
+            x = range(tx_product.shape[0])[peaks[0] - 50:peaks[0] + 50]
             ax.plot(x, tx_product_crop)
             ylim = ax.get_ylim()
             ax.plot((peaks[0], peaks[0]), (ylim[0], ylim[1]))
@@ -113,38 +139,16 @@ class Symbol_align:
         # of the shift to find the offset of the symbol start.
         return (offset + self.c.T_C) % self.c.T_S
 
-    def _remove_outliers(self, x, stds=5):
-        deviation_from_mean = np.abs(x - np.mean(x))
-        inlier_idxs = deviation_from_mean < stds * np.std(x)
-        x = x[inlier_idxs]
-        return x
-
-    def _calc_delta_angle(self, fft):
-        # Introduce invariance against carrier
-        angles = np.angle(fft) % (np.pi / 2.)
-
-        # Calculate Angle difference and compensate jumps
-        deltas_angle = np.diff(angles)
-        deltas_angle[deltas_angle > np.pi/4.] =\
-            deltas_angle[deltas_angle > np.pi/4.] - np.pi/2.
-        deltas_angle[-deltas_angle > np.pi/4.] = \
-            deltas_angle[-deltas_angle > np.pi/4.] + np.pi/2.
-        deltas_angle = self._remove_outliers(deltas_angle)
-
-        delta_angle = np.mean(deltas_angle)
-
-        return delta_angle
-
     def _delta_angle_to_samples(self, angle):
         return - angle / self.c.phase_offset_per_sample
 
-    def _calc_sample_offset(self, sig, debug=False):
-        assert sig.shape[0] == self.c.T_U,\
+    def _calc_sample_offset(self, sig):
+        assert sig.shape[0] == self.c.T_U, \
             "Input length is not a Symbol without cyclic prefix"
 
         fft = np.fft.fftshift(np.fft.fft(sig))
         fft_crop = np.delete(fft[self.c.FFT_start:self.c.FFT_end], self.c.FFT_delete)
-        delta_angle = self._calc_delta_angle(fft_crop)
+        delta_angle = _calc_delta_angle(fft_crop)
         delta_sample = self._delta_angle_to_samples(delta_angle)
         delta_sample_int = np.round(delta_sample).astype(int)
         error = np.abs(delta_sample_int - delta_sample)
@@ -154,6 +158,7 @@ class Symbol_align:
         return delta_sample_int
 
     def calc_offset(self, tx):
+        """Calculate the offset the first symbol"""
         off_sym = self._calc_offset_to_first_symbol_without_prefix(
             tx)
         off_sam = self._calc_sample_offset(
@@ -168,7 +173,7 @@ class Symbol_align:
         off = self.calc_offset(tx)
         return tx[
                off:
-               off+self.c.T_U
+               off + self.c.T_U
                ]
 
 # The MIT License (MIT)