scripts in Audacity 2.1.0

Hello.
I use Audacity 2.1.0 under Windows Vista 64 bits and Windows 8.1.
I have a question has to rest.
It is possible to edit an audio file with a chain of effects in Audacity 2.1.0.
I would want to know if there is a Nyquist plug-in whom would allow at a moment of the chain of effect, to edit simply a part of the edited audio file.
For example the first half, or the first two seconds. When we edit a file, we edit all the file. It is as well very interesting, to be able to edit at a moment of the chain of effects as a part of the audio file.
Thank you for your answer.
Sorry for the english.

If when you apply the Chain you choose “Apply to Files…” then the whole of the file is affected by the commands in the Chain. A few Nyquist plugins which you can add to Audacity can process the whole selection but only act on part of it, for example Trim Silence.

If when you apply the Chain you choose “Apply to Current Project” and if the project has a selection region then the Chain applies only to that selection.

See Chains - for batch processing and effects automation - Audacity Manual.

Do you wish to request that Chains applied to files can choose a selection to work on?

Gale

Yes it is. See: Audacity Manual

Yes, but with limitations.
Currently to do that the entire audio file would need to be loaded into RAM (in 32 bit float format), and I believe is limited to a maximum of 2 GB. There is also the difficulty that in the absence of user input the plugin may not know which part of the track you want to process. Taking those considerations into account, yes it is feasible for a Nyquist plugin to change just a certain part of the track, but the entire track would be processed, even if most of it was “processed” with “null effect” (same data out as goes in).

yes that is possible, but as above, the current versions of Nyquist plugins need to load the entire track in order to access a specified section. It is hoped that the next generation of Nyquist plugins will be able to access specified sections of a track without loading the entire track, but we don’t have that yet in Audacity.