demo_filterbank.py: add simple filterbank demo

diff --git a/interfaces/python/demo_filterbank.py b/interfaces/python/demo_filterbank.py
new file mode 100644 (file)
index 0000000..012777f
--- /dev/null
+++ b/interfaces/python/demo_filterbank.py
@@ -0,0 +1,13 @@
+from _aubio import filterbank
+from numpy import array
+
+f = filterbank(9, 1024)
+freq_list = [40, 80, 200, 400, 800, 1600, 3200, 6400, 12800, 15000, 24000]
+freqs = array(freq_list, dtype = 'float32')
+f.set_triangle_bands(freqs, 48000)
+f.get_coeffs().T
+
+from pylab import loglog, show
+loglog(f.get_coeffs().T, '+-')
+show()
+