Nyquist Basics: The Audacity Nyquist Prompt

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Revision as of 06:36, 11 February 2008 by Edgar-rft (talk | contribs) (added section 'The Nyquist Prompt')
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With the Audacity Nyquist Prompt you can test small snippets of Nyquist code or doing quick audio hacks. On this page the basic usage of the Nyquist prompt is explained.
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The Audacity Nyquist prompt is placed in the Audacity "Effect" menu which only can be activated if an Audacity audio track exists and at least a part of it marked or selected.

Load a Sound File

If you have a mono or stereo sound file available you can load it into Audacity via:

  • Audacity File menu > Import > Audio   or   Shift + Control + I

If you have no sound files available you can build your own mono or stereo tracks via the Audacity "Generate" menu.

Create a Mono Track

Go to the Audacity "Generate" menu and choose "Tone". Leave everything as-is, just click "OK", a mono track will appear in the Audacity window:


Create a Stereo Track

1. Mark the whole mono track from above either by pressing "Ctrl+A" on the keyboard, or by clicking with the mouse into the track header, with taking care not to move the buttons or sliders, the whole track then will appear in a different color.

2. Go to the "Edit" menu and choose "Duplicate". A second, identical mono track will appear below the first one:


3. In the upper mono track, open the track menu by clicking on the small black triangle at the top of the track header and coose "Make stereo track". Both mono tracks then will get combined to a single stereo track:


The Nyquist Prompt

To enable the Audacity "Effect" menu at least a part of an Audacity audio track must be marked or selected. Then go to the Audacity "Effect" menu and choose "Nyquist prompt". A window like the following will appear.

The Nyquist Interpreter

In the "Nyquist Prompt" window, type into the text field a string "hello" with quotes:

If you click "OK", you should get a window displaying the word hello:

Click "OK" in the "hello" window to make it disappear again.

Congratulations, you just have learned how to send text messages to the user.

The Nyquist Debugger

After clicking "OK" in the "hello" window, go back to the Audacity "Effect" menu and choose "Nyquist prompt" again, but this time type the word hello without the quotes:

Important: Now click "Debug" instead of "OK".

You should first get a window displaying a "Nyquist did not return audio" or similar message:

After clicking "OK" in the window above, a second window appears, displaying the detailed Nyquist error messages:

Important: The "Nyquist output" window only appears if you click "Debug" in the "Nyquist Prompt" window. If you click "OK", then, even with a Nyquist error, only the first window will appear.