From: Paul Brossier <piem@piem.org>
Date: Tue, 15 Oct 2013 21:22:00 +0000 (+0200)
Subject: python/demos/demo_filterbank.py: added simple filterbank demo
X-Git-Tag: 0.4.0-beta1~110^2~17
X-Git-Url: https://git.aubio.org/?a=commitdiff_plain;h=735a7394485494e3064f653c2096576d2db4b0d2;p=aubio.git

python/demos/demo_filterbank.py: added simple filterbank demo
---

diff --git a/python/demos/demo_filterbank.py b/python/demos/demo_filterbank.py
new file mode 100755
index 00000000..7080864b
--- /dev/null
+++ b/python/demos/demo_filterbank.py
@@ -0,0 +1,30 @@
+#! /usr/bin/python
+
+from aubio import filterbank, fvec
+from pylab import loglog, show, subplot, xlim, ylim, xlabel, ylabel, title
+from numpy import vstack, arange
+
+win_s = 2048
+samplerate = 48000
+
+freq_list = [60, 80, 200, 400, 800, 1600, 3200, 6400, 12800, 24000]
+n_filters = len(freq_list) - 2
+
+f = filterbank(n_filters, win_s)
+freqs = fvec(freq_list)
+f.set_triangle_bands(freqs, samplerate)
+
+coeffs = f.get_coeffs()
+coeffs[4] *= 5.
+
+f.set_coeffs(coeffs)
+
+times = vstack([arange(win_s / 2 + 1) * samplerate / win_s] * n_filters)
+title('Bank of filters built using a simple list of boundaries\nThe middle band has been amplified by 2.')
+loglog(times.T, f.get_coeffs().T, '.-')
+xlim([50, samplerate/2])
+ylim([1.0e-6, 2.0e-2])
+xlabel('log frequency (Hz)')
+ylabel('log amplitude')
+
+show()