1 files changed, 71 insertions, 0 deletions
diff --git a/python/demos/demo_pitch_sinusoid.py b/python/demos/demo_pitch_sinusoid.py
new file mode 100755
index 0000000..629f327
--- /dev/null
+++ b/python/demos/demo_pitch_sinusoid.py
@@ -0,0 +1,71 @@
+#! /usr/bin/env python
+
+import numpy as np
+import aubio
+
+def build_sinusoid(length, freqs, samplerate):
+    return np.sin( 2. * np.pi * np.arange(length) * freqs / samplerate).astype(aubio.float_type)
+
+def run_pitch(p, input_vec):
+    cands = []
+    for vec_slice in input_vec.reshape((-1, p.hop_size)):
+        a = p(vec_slice)[0]
+        cands.append(a)
+    return cands
+
+methods = ['default', 'schmitt', 'fcomb', 'mcomb', 'yin', 'yinfft']
+
+cands = {}
+buf_size = 2048
+hop_size = 512
+samplerate = 44100
+sin_length = (samplerate * 10) % 512 * 512
+freqs = np.zeros(sin_length)
+
+partition = sin_length // 8
+pointer = 0
+
+pointer += partition
+freqs[pointer: pointer + partition] = 440
+
+pointer += partition
+pointer += partition
+freqs[ pointer : pointer + partition ] = 740
+
+pointer += partition
+freqs[ pointer : pointer + partition ] = 1480
+
+pointer += partition
+pointer += partition
+freqs[ pointer : pointer + partition ] = 400 + 5 * np.random.random(sin_length/8)
+
+a = build_sinusoid(sin_length, freqs, samplerate)
+
+for method in methods:
+    p = aubio.pitch(method, buf_size, hop_size, samplerate)
+    cands[method] = run_pitch(p, a)
+    print(method)
+    print(cands[method])
+
+print("done computing")
+
+if 1:
+    import matplotlib.pyplot as plt
+
+    # times
+    ramp = np.arange(0, sin_length / hop_size).astype('float') * hop_size / samplerate
+
+    # plot each result
+    for method in methods:
+        plt.plot(ramp, cands[method], '.-', label=method)
+
+    # plot ground truth
+    ramp = np.arange(0, sin_length).astype('float') / samplerate
+    plt.plot(ramp, freqs, ':', label = 'ground truth')
+
+    plt.legend(loc='upper left')
+
+    plt.xlabel('time (s)')
+    plt.ylabel('frequency (Hz)')
+    plt.ylim([0,2000])
+    plt.show()