Ok, but where does On 23 June 2014 22:59, robert bristow-johnson <r...@audioimagination.com> wrote: > On 6/23/14 10:50 AM, Andrew Simper wrote: >> >> Ok, I'm still stumped here. Can someone please show me a reference to >> how the bi-linear transform is created without using trapezoidal >> integration? > > > not that you wanna hear from me, but the usual "derivation" in textbooks > goes something like this: > > > z = e^(sT) > > = e^(sT/2) / e^(-sT/2) > > =approx (1 + sT/2)/(1 - sT/2) (hence the "bilinear" approximation) > > > solving for s gets > > > s =approx 2/T * (z-1)/(z+1) >
Ok, but what are the origins of that approximation? Where did it actually come from. Looking at it in hindsight is fine, but doesn't tell me anything. -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
