class MyCosine extends Chugen
{
    0 => int p;
    440 => float f;
    second/samp => float SRATE;
    fun float tick(float in)  { return Math.cos(p++*2*pi*f/SRATE); }
    fun void setFreq(float freq) { freq => f; };
}

MyCosine m => dac;

1.0 :: second => now;

1000.0 => m.setFreq;

1.0 :: second => now;