src/ria_toolkit_oss/view/view_signal.py

@@ -1,3 +1,4 @@
+import gc
 import os
 import textwrap
 from typing import Optional
@@ -8,6 +9,7 @@ from matplotlib import gridspec
 from PIL import Image
 from scipy.fft import fft, fftshift
 from scipy.signal import spectrogram
+from scipy.signal.windows import hann
 
 from ria_toolkit_oss.datatypes.recording import Recording
 from ria_toolkit_oss.view.tools import (
@@ -122,7 +124,7 @@ def view_sig(
         plot_y_indx = plot_y_indx + 2
         fft_size = get_fft_size(plot_length=plot_length)
 
-        f, t_spec, Sxx = spectrogram(
+        _, t_spec, Sxx = spectrogram(
             complex_signal[:plot_length],
             fs=sample_rate,
             nperseg=fft_size,
@@ -132,14 +134,16 @@ def view_sig(
         )
 
         # shift frequencies so zero is centered
+        f_bins = np.fft.fftfreq(fft_size, d=1.0 / sample_rate)
+        f_bins = np.fft.fftshift(f_bins)
+        f_bins = f_bins + center_frequency
         Sxx = np.fft.fftshift(Sxx, axes=0)
-        f = np.fft.fftshift(f) - sample_rate / 2 + center_frequency
 
         spec_ax.imshow(
             10 * np.log10(Sxx + 1e-12),
             aspect="auto",
             origin="lower",
-            extent=[t_spec[0], t_spec[-1], f[0], f[-1]],
+            extent=[t_spec[0], t_spec[-1], f_bins[0], f_bins[-1]],
             cmap="twilight",
         )
 
@@ -169,18 +173,17 @@ def view_sig(
         freq_ax = plt.subplot(gs[plot_y_indx : plot_y_indx + 2, :])
         plot_y_indx = plot_y_indx + 2
 
-        epsilon = 1e-10
+        # Apply window to reduce spectral leakage
-        spectrum = np.abs(fftshift(fft(complex_signal[0:plot_length])))
+        window = hann(len(complex_signal[:plot_length]))
-        freqs = (
+        spectrum = np.abs(fftshift(fft(complex_signal[:plot_length] * window)))
-            np.linspace(-1 * (sample_rate / 2), (sample_rate / 2), len(complex_signal[0:plot_length]))
-            + center_frequency
-        )
 
-        # Use semi-log for the y-axis
+        # Convert to dB
-        freq_ax.semilogy(freqs, spectrum + epsilon, color=COLORS["accent"], linewidth=0.8)
+        spectrum_db = 20 * np.log10(spectrum + 1e-12)  # 20*log for magnitude
-        freq_ax.set_xlabel("Frequency")
+
-        freq_ax.set_ylabel("Magnitude")
+        freqs = np.linspace(-sample_rate / 2, sample_rate / 2, len(complex_signal[:plot_length])) + center_frequency
-        freq_ax.set_title("Frequency Spectrum", fontsize=subtitle_fontsize)
+        freq_ax.plot(freqs, spectrum_db, color=COLORS["accent"], linewidth=0.8)
+        freq_ax.set_ylabel("Magnitude (dB)")
+        freq_ax.set_title("Frequency Spectrum (Windowed FFT)", fontsize=subtitle_fontsize)
         set_spines(freq_ax, spines)
 
     if constellation:
@@ -255,3 +258,7 @@ def view_sig(
     output_path, _ = set_path(output_path=output_path)
     plt.savefig(output_path, dpi=dpi)
     print(f"Saved signal plot to {output_path}")
+
+    # Garbage collection and clean up to prevent memory overloading
+    plt.close("all")
+    gc.collect()

src/ria_toolkit_oss/view/view_signal_simple.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import gc
 from typing import Optional
 
 import matplotlib
@@ -318,6 +319,10 @@ def view_simple_sig(
         return output_path
 
     plt.show()
+
+    # Garbage collection and clean up to prevent memory overloading
+    plt.close("all")
+    gc.collect()
     return None