[sc-dev] Re: frac semantic

[Julian Rohrhuber <rohrhuber@xxxxxxxxxxxxxx>]

sorry, even after rereading the thread, I don't get it. A change of 
semantics implies a change of behaviour. Or do you mean you want to 
change the implementation without changing the behaviour?


At 11:32 Uhr -0800 17.12.2009, Scott Carver wrote:
> The lang version of .frac is equivalent to n%1.

this is not so, at least in my build:

-1.2.frac // -0.2
1.2.frac // 0.2

-1.2 % 1 // 0.8
1.2 % 1 // 0.2

f = FunctionList([{ |x| x - floor(x) }, _.frac, _ % 1]);
f.([1.2, 0, -1.2]);

// [ [ 0.2, 0, 0.8 ], [ 0.2, 0, -0.2 ], [ 0.2, 0, 0.8 ] ]





> On 12/21/2009 11:47 AM, Julian Rohrhuber wrote:
> > >  The lang version of .frac is equivalent to n%1. In terms of
> > >  usefulness, then, it might be better to go with the ugen definition
> > >  of .frac, so both possibilities are covered.
> >
> >
> >  The lang version currently is the same as the ugen version:
> >
> >
> >
> >  -1.2.frac // -0.2
> >  1.2.frac // 0.2
> >  { DC.ar(-1.2).frac.poll }.play; // -0.2
> >  { DC.ar(1.2).frac.poll }.play; // 0.2
>
> you may want to check the sources. the ugen implements arg - floor(arg),
> the language as arg - trunc(arg). the trunc implementation relies on a
> specific rounding mode ... since it is not set, the trunc implementation
> doesn't necessarily behave as it should.
>
> > >  yes, i would also prefer this behavior ... if no one objects, i will
> > >  commit a patch, changing the sclang semantic of frac to match the unit
> > >  generator ...
> >
> >  so what of the above behavior is changed by your patch?
>
> arg - floor(arg), as described earlier in this thread
>
> tim
>
> --
> tim@xxxxxxxxxx
> http://tim.klingt.org
>
> Happiness is a byproduct of function, purpose, and conflict; those who
> seek happiness for itself seek victory without war.
>   William S. Burroughs
>
>
> Content-Type: application/pgp-signature; name="signature.asc"
> Content-Description: OpenPGP digital signature
> Content-Disposition: attachment; filename="signature.asc"
>
> Attachment converted: data:signature 1131.asc (    /    ) (00051D25)


--





.

_______________________________________________
sc-dev mailing list

info (subscription, etc.): http://www.beast.bham.ac.uk/research/sc_mailing_lists.shtml
archive: https://listarc.bham.ac.uk/marchives/sc-dev/
search: https://listarc.bham.ac.uk/lists/sc-dev/search/