i would also like to add that A and K rates usually seem to be assigned
variables that are series (or arrays).  I rate variables are generally just
one number.
example:

ivar  =  4.5
avar  oscil 1000, 1000, 1
kvar  oscil 1000, 1000, 1

pete


rasmus ekman wrote:

> David Schuyeteneer wrote:
> >
> > Can someone please explain me very clear and exactly what those
> > weird A -, K - and I - RATES are ???
>
> A-rate in Csound means audio rate, ie generated soundfile sample rate.
> Sample rate in a digital sound file decides the sound quality.
> Common values are: 44100 Hz (CD rate), 22050 Hz (usually ok when testing
> an instrument), or 8000 Hz (web .au files - only good for speech)
> K-rate means "Control" rate. The ear cannot detect most musical changes
> (like pitch change) at a very high rate. Csound saves computing time by
> updating many variables at a slower rate. For most purposes 1/10th or
> even 1/100th of audio rate will do fine. At lower rates the stepping in
> the variable changes will be too annoying.
>
> I-rate is for init time. This is not properly a rate, it's for setting
> a variable to an initial value when an instrument begins playing.
>
> Regards,
>
>         re

On Wed, 17 Dec 1997, pete moss wrote:

> i would also like to add that A and K rates usually seem to be assigned
> variables that are series (or arrays).  I rate variables are generally just
> one number.
> example:
> 
> ivar  =  4.5
> avar  oscil 1000, 1000, 1
> kvar  oscil 1000, 1000, 1
> 
> pete
> 
	This is basically wrong.  There are some opcodes (like oscil)
which do not run at i rate.  It would be meaningless to read an oscillator
just once at the beginning of a note.  However, many other opcodes (e.g.
the various random generators) are often used at i rate.  There is no
correlation between the number of arguments an opcode takes and its
available rates.

(addendum: There are possible uses for a instrument rate oscil, but in
Csound, this would be part of the score, not the orchestra)

Mike Berry
mikeb@nmol.com