Changeset eff63ab


Ignore:
Timestamp:
Nov 4, 2018, 9:00:31 PM (13 months ago)
Author:
Paul Brossier <piem@piem.org>
Branches:
feature/autosink, feature/constantq, feature/pitchshift, feature/pydocstrings, feature/timestretch, master
Children:
5f2f459
Parents:
254acce
Message:

[py] improve style for demo_filterbank.py

File:
1 edited

Legend:

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  • python/demos/demo_filterbank.py

    r254acce reff63ab  
    11#! /usr/bin/env python
    22
    3 from aubio import filterbank, fvec
    4 from pylab import loglog, show, xlim, ylim, xlabel, ylabel, title
    5 from numpy import vstack, arange
     3"""Create a filterbank from a list of frequencies.
    64
     5This demo uses `aubio.filterbank.set_triangle_bands` to build a set of
     6triangular filters from a list of frequencies.
     7
     8The filterbank coefficients are then modified before being displayed."""
     9
     10import aubio
     11import numpy as np
     12import matplotlib.pyplot as plt
     13
     14# sampling rate and size of the fft
     15samplerate = 48000
    716win_s = 2048
    8 samplerate = 48000
    917
     18# define a list of custom frequency
    1019freq_list = [60, 80, 200, 400, 800, 1600, 3200, 6400, 12800, 24000]
     20# number of filters to create
    1121n_filters = len(freq_list) - 2
    1222
    13 f = filterbank(n_filters, win_s)
    14 freqs = fvec(freq_list)
     23# create a new filterbank
     24f = aubio.filterbank(n_filters, win_s)
     25freqs = aubio.fvec(freq_list)
    1526f.set_triangle_bands(freqs, samplerate)
    1627
     28# get the coefficients from the filterbank
    1729coeffs = f.get_coeffs()
    18 coeffs[4] *= 5.
    19 
     30# apply a gain to fifth band
     31coeffs[4] *= 6.
     32# load the modified coeffs into the filterbank
    2033f.set_coeffs(coeffs)
    2134
    22 times = vstack([arange(win_s // 2 + 1) * samplerate / win_s] * n_filters)
    23 title('Bank of filters built using a simple list of boundaries\nThe middle band has been amplified by 2.')
    24 loglog(times.T, f.get_coeffs().T, '.-')
    25 xlim([50, samplerate/2])
    26 ylim([1.0e-6, 2.0e-2])
    27 xlabel('log frequency (Hz)')
    28 ylabel('log amplitude')
    29 
    30 show()
     35# display the band gains in a loglog plot
     36freqs = np.vstack([np.arange(win_s // 2 + 1) * samplerate / win_s] * n_filters)
     37plt.title('filterbank built from a list of frequencies\n'
     38          'The 5th band has been amplified by a factor 6.')
     39plt.loglog(freqs.T, f.get_coeffs().T, '.-')
     40plt.xlim([50, samplerate/2])
     41plt.ylim([1.0e-6, 2.0e-2])
     42plt.xlabel('log frequency (Hz)')
     43plt.ylabel('log amplitude')
     44plt.show()
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