Moved the plotting of symbol boundaries out to its own function

matlab/automatic_detector.m

@@ -98,53 +98,7 @@ true_start_index = round(start_offset/decimation_rate);
 %  over a time domain view of the burst.  It alternates between red and
 %  green transparent rectangles over the time domain as a sanity check that
 %  the time alignment is correct (starting at the right sample)
-
-% Plot the time domain
-figure(4);
-plot(10 * log10(abs(samples)));
-
-% Tranceparency of each box (so the waveform is still visible)
-face_opacity = 0.25;
-
-% Don't show the lines between the boxes.  Just gets in the way
-edge_color = [0, 0, 0, 0];
-
-% Define the box colors (with transparency)
-face_color_red   = [1, 0, 0];
-face_color_green = [0, 1, 0];
-
-% The Y axis of the plot is in dB, so draw a box that starts at -30 dB and
-% goes up by 25 dB (-5 dB).  These numbers just happened to work out with
-% the test data and will likely change for other collects
-box_y_start = -30;
-box_y_height = 25;
-
-% Draw the first rectangle over the only symbol that uses a long cyclic
-% prefix
-r = rectangle('Position', [1, box_y_start, fft_size + long_cp_len, box_y_height]);
-set(r, "FaceColor", face_color_red);
-set(get(r, 'children'), "FaceAlpha", face_opacity);
-% rectangle('Position', [1, box_y_start, fft_size + long_cp_len, box_y_height], ...
-%           'FaceColor', face_color_red, ...
-%           'EdgeColor', edge_color);
-
-% Draw the remaining boxes over the OFDM symbols that use the short cyclic
-% prefix, alternating between colors
-for symbol_idx=1:8
-    if (mod(symbol_idx, 2) == 0)
-        color = face_color_red;
-    else
-        color = face_color_green;
-    end
-
-    relative_offset = symbol_idx * (fft_size + short_cp_len);
-    r = rectangle('Position', [1 + relative_offset, box_y_start, fft_size + short_cp_len, box_y_height]);
-    set(r, "FaceColor", color);
-    set(get(r, 'children'), "facealpha", face_opacity);
-%               'FaceColor', color, ...
-%               'EdgeColor', edge_color);
-end
-title('OFDM Symbol Boundaries')
+plot_symbol_boundaries(samples, critial_sample_rate, 4);
 
 %% Coarse frequency adjustment
 offset_freq = -.156e3;

matlab/plot_symbol_boundaries.m

@@ -0,0 +1,45 @@
+function [] = plot_symbol_boundaries(samples, sample_rate, figure_num)
+    long_cp_len = round(1/192000 * sample_rate);
+    short_cp_len = round(0.0000046875 * sample_rate);
+    fft_size = sample_rate / 15e3;
+
+    % Plot the time domain
+    figure(figure_num);
+    plot(10 * log10(abs(samples)));
+    
+    % Tranceparency of each box (so the waveform is still visible)
+    face_opacity = 0.25;
+    
+    % Don't show the lines between the boxes.  Just gets in the way
+    edge_color = [0, 0, 0, 0];
+    
+    % Define the box colors (with transparency)
+    face_color_red   = [1, 0, 0];
+    face_color_green = [0, 1, 0];
+    
+    % The Y axis of the plot is in dB, so draw a box that starts at -30 dB and
+    % goes up by 25 dB (-5 dB).  These numbers just happened to work out with
+    % the test data and will likely change for other collects
+    box_y_start = -30;
+    box_y_height = 25;
+    
+    for symbol_idx=0:8
+        if (mod(symbol_idx, 2) == 0)
+            color = face_color_red;
+        else
+            color = face_color_green;
+        end
+    
+        relative_offset = symbol_idx * (fft_size + short_cp_len);
+        r = rectangle('Position', [1 + relative_offset, box_y_start, fft_size + short_cp_len, box_y_height]);
+
+        if (exist('OCTAVE_VERSION', 'builtin'))
+            set(r, "FaceColor", color);
+            set(get(r, 'children'), "facealpha", face_opacity);
+        else
+            set(r, "FaceColor", [color, face_opacity]);
+        end
+    end
+
+    title('OFDM Symbol Boundaries')
+end