>> -Also, the variable "fc" is the corner frequency. What is that on how do
>> I set it???
> In a band stop filter fc is the center frequency of the stop band. In
> your transfer function everything is scaled in time, with "To". For fc
> in Hz, fc = 1/(2 * pi * To).
Remember to prewarp the critical frequencies. Rick's book goes into it,
and so do many other sources. Robert Bristow-Johnson wrote a clear
description (in comp.dsp, I think); Google should turn it up. If not,
Tim or I can describe the process, the equation is simple.
Engineering is the art of making what you want from things you can get.