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Original file (544 × 662 pixels, file size: 33 KB, MIME type: image/png)
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Summary
| Description |
English: The power spectral density of a segment of music is estimated by two different methods, for comparison.
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| Date | ||||
| Source | Own work | |||
| Author | Bob K | |||
| Permission (Reusing this file) |
I, the copyright holder of this work, hereby publish it under the following license:
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| PNG development |  This PNG graphic was created with LibreOffice. |
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| Octave/gnuplot source | click to expand
This graphic was created with the help of the following Octave script: graphics_toolkit gnuplot
pkg load signal
load 'music.mat' % adds variables wavedata and samplerate to the workspace
whos % displays the workspace
%{music.mat was created by these steps in program Audacity:
• Open a stereo mp3 file.
• Right-click on the filename, and choose Split Stereo to Mono in the drop-down menu.
• Delete one channel.
• Highlight a section to be exported.
• Choose Export Selected Audio.
• Choose Save As Type: Other Uncompressed Files.
• Under Options, set Header=MAT5 and Encoding=Signed 16-bit PCM
%}
periodogram (wavedata, [], 512, samplerate, 'twosided')
grid on
xlim([0 samplerate])
title("Periodogram",'FontSize', 14)
xlabel('Frequency (Hz)','FontSize', 14)
ylabel('Amplitude (dB)','FontSize', 14)
figure
pwelch(wavedata, hann(512), 0.25, 512, samplerate, 'twosided', 'dB')
grid on
xlim([0 samplerate])
ylim([-60 60])
title("Welch's method",'FontSize', 14)
xlabel('Frequency (Hz)','FontSize', 14)
ylabel('Amplitude (dB)','FontSize', 14)
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File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 20:07, 24 October 2016 | | 544 × 662 (33 KB) | Bob K | User created page with UploadWizard |
File usage
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Global file usage
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- Usage on ca.wikipedia.org
