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# Nyquist Prompt

From Audacity Development Manual

Nyquist Prompt lets you run and debug code snippets for your own plug-ins created using the Nyquist programming language. See the Manual\'s Nyquist page for more information about writing Nyquist code. See also the Audacity wiki page on Nyquist
To process audio with Nyquist commands, first select some audio.

  Accessed by: Tools > Nyquist Prompt...

## Enter Nyquist Command

Type the command as required. Enter on the keyboard moves the cursor to a new line. The last entered code is stored in the pluginsettings.cfg file in Audacity\'s folder for application data so is retained after exiting Audacity.

Plugin GUI can be tested if you include complete Nyquist Plug-in Headers. The Nyquist Prompt interprets header comments to produce a plug-in of the defined type on the fly. By default the plug-in is a process type, though other type may be created by including the appropriate header.

## Use legacy (version 3) syntax

When selected, commands entered in the main text window will be interpreted as the "version 3" code. Support for version 3 syntax is provided for backward compatibility only and is not recommended for new code. When not selected (default), commands entered in the main text window will be interpreted as "version 4" code.

Version 4 code includes a number of variables that are not available in version 3. In particular, the S variable is no longer used to pass sound from Audacity to Nyquist. In version 4 the S variable has been replaced by *TRACK*. Full details about the difference between version 3 and version 4 code can be found in the Audacity wiki.

## Buttons

### Editing or making Nyquist plug-ins

- Load Load a Nyquist plugin or script file saved with .ny extension.
- Save Save the current contents of the editor window as an .ny file.

### Presets

- Manage Opens a dropdown menu where you can save the window contents as a preset then reload those contents by selecting the preset. You can also see some descriptive text about the plugin. For details see Manage presets.

### Others

- Debug Clicking this button redirects error messages from Audacity\'s error log to a non-editable "Debug" window. An empty debug windows indicates that no errors were detected. Click OK to close the debug window, or using the keyboard; hold Ctrl on Windows (or ⌘ on Mac) then press Enter.
- OK Applies the code to the waveform selection without debug output. Your entered code will be retained next time you open Nyquist Prompt in the Audacity session. Using the keyboard hold Ctrl on Windows (or ⌘ on Mac) then press Enter. Using the keyboard on Linux, hold down Alt and press o.
- Cancel No code is processed or debugged. Any code you entered after opening the window this time will be discarded.

The Nyquist prompt supports both LISP syntax and SAL syntax. If the code you enter cannot be recognized as valid Nyquist code in either LISP or SAL syntax, an error message will appear with a hint about making a correction.

## Links

|< Index of Effects, Generators and Analyzers

|< Effect Menu

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