Hi Alex,

You are correct and you can not use a loop to do what you want.  This
being able to delay x number of signals isn't a straightforward thing
to do in csound.  When you call an opcode, you can imagine it being
like an object and that you are calling something like
vdelay.process(x).  If you think of it this way, it means each time
you call it, you are advancing its internal state by one step in the
processing.  Normally this is the expected behavior that you call it
once per k- count, but if you call it multiple times the behavior
won't be what you're expecting.

For Csound, any time you want to process x number of signals (process
a variable amount of signals) you'll need to use a recursive User
Defined Opcode (UDO).  It's the only way to setup things correctly and
can be tricky if you are not experienced with recursive algorithms (I
don't know your background).  Your example does not vary the delay
times so I can't really suggest a complete solution, but something
like:

opcode recurseVdelay 0, kii

kdelay, izakstart, izakend xin
azak zar izakstart
adelay vdelay azak, kdelay, 5000
zaw adelay, izakstart

if (izakstart <= izakend) then
recurseVdelay kdelay, izakstart + 1, izakend
endif

endop

then call it in instr code like:

recurseVdelay kdelay, 0, izakspace

I haven't tried the above code but I think it'll work.

steven


p.s. - If you haven't checked them out already, I wrote two articles
for the Csound Journal on control flow which describes loops and
recursive UDO's:

http://www.csounds.com/journal/2006spring/controlFlow.html
http://www.csounds.com/journal/2006summer/controlFlow_part2.html

The whole thing about loops and why you can't call most opcodes in
loops is explained in part2 in discussing when to use recursion.


On 9/16/07, Alex Weiss <alexweiss@freesurf.ch> wrote:
> Hi everybody
>
> I'm currently working on a Csound instrument, but there's something
> that I just don't know how to implement:
> If have a zak array that holds quite a few a-rate signals. Now, what I
> basically want to do is delay each of these signals (with different
> delay times) and write them back into the zak space. The following
> code obviously doesn't work:
>
> (kr = sr)
>
>
> kcount = 1
>
>         loop:
>                 azak zar kcount
>                 adelay vdelay azak, kdelay, 5000
>                 zaw adelay, kcount
>                 kcount = kcount + 1
>         if (kcount <= izakspace) kgoto loop
>
>
>
> It seems that there is no way that I can use a loop to perform the
> operation (which was the reason I chose to work with zak to begin
> with...). Do I really have to delay every signal manually?
>
> I hope somebody can help me out here... Thank you in advance.
>
> Alex
>
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