The simplest way is to use portk or tonek.
This won't give you a linear sweep though,
for that you would use a line opcode and reinit, admittedly a bit
kludgy but could maybe be put into a UDO (if there's not one tht does
this already).
Oeyvind


2007/8/26, Greg Thompson <greg@rhythmicdesign.com>:
>
>
> gisin ftgen 0, 0, 4096, 10, 1, 0.5, 0.25, 0.125, 0.0625, 0.03125, 0.015625
>
>     instr 10
> iBasePitch = p4
>
> kFreePitch  chnget "Pitch"
> kAmpChannel chnget "Amp"
>
> kPitch  = cpspch(iBasePitch + kFreePitch)
>
> aAmp    interp  kAmpChannel
>
> aAmp    = ampdbfs(aAmp)
>
> kEnv    line    1.0, p3, 0.0
>
> a1      oscili aAmp * kEnv, kPitch, gisin
>
>         outs a1, a1
>
>     endin
>
>
>
>
> So, I have a slider representing pitch and amplitude.  I'm using channels to
> pass values into the orchestra.  So, in this case, I'm using the chnget
> opcode.
>
> I'm wondering how I do some simple form of interpolation so if I get a value
> of 1.0 at time t1 and then 2.0 at time t2.  It gradual shifts from 1.0 to
> 2.0 over a slew time.  In Max, I would use the line object.
>
> Can one suggest a proper way to do this in Csound?
>
> thanks
> greg