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Re: laplace tranform convert to code

Started by Tim Wescott July 24, 2006
Jerry Avins wrote:

> Tim Wescott wrote: > >> tim w wrote: > > > ... > >>> -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). > > > Other tim, > > 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. > > Jerry
Check his original URL: The author has a clever way of building the prewarping into the bilinear transform. Dunno if I'd want to make a habit of using it, but it's cute. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Posting from Google? See http://cfaj.freeshell.org/google/ "Applied Control Theory for Embedded Systems" came out in April. See details at http://www.wescottdesign.com/actfes/actfes.html