Hi, Matlab has a function called iirgrpdelay which helps in designing iir group delay equalizer filters. Any idea as to how this function can be re-written for people who are not using matlab? Bharat Pathak
group delay equalizer
Started by ●January 13, 2008
Reply by ●January 13, 20082008-01-13
"bharat pathak" <bharat@arithos.com> wrote in message news:fs-dnX5z64XJUBTanZ2dnUVZ_hCdnZ2d@giganews.com...> Hi, > > Matlab has a function called iirgrpdelay which helps > in designing iir group delay equalizer filters.This is a shamanistic optimization which tries to match the group delay profile by the brute force tweaking of an allpass function.> Any idea as to how this function can be re-written > for people who are not using matlab?I am glad to see that there are still some real people who dare to live without MatLab. Vladimir Vassilevsky DSP and Mixed Signal Consultant www.abvolt.com
Reply by ●January 14, 20082008-01-14
On Jan 13, 3:35 am, "bharat pathak" <bha...@arithos.com> wrote:> > Matlab has a function called iirgrpdelay which helps > in designing iir group delay equalizer filters. > > Any idea as to how this function can be re-written > for people who are not using matlab? >i can only suggest to start with the MATLAB source code (i might have an old copy) for iirgrpdelay() and all functions that it depends on, and translate to C or whatever language you like. remember the stupid MATLAB indexing origin property. you might be adjusting some indices by 1. you know, probably everyone here has some C++ programming enviroment: VC++, Objective-C, GNU. they already have C++ classes for math using complex variables and matrices. probably, there exists some nice utilities to plot functions of one or two variables and to input and output audio to/from hardware or files. someone should add the simple functionality of most of the SP Toolbox to these classes in C++. lot'sa work. i can't do it. r b-j
Reply by ●January 14, 20082008-01-14
"bharat pathak" <bharat@arithos.com> writes:> Hi, > > Matlab has a function called iirgrpdelay which helps > in designing iir group delay equalizer filters. > > Any idea as to how this function can be re-written > for people who are not using matlab? > > Bharat PathakYou check to see if it's available in gnu octave. -- % Randy Yates % "Remember the good old 1980's, when %% Fuquay-Varina, NC % things were so uncomplicated?" %%% 919-577-9882 % 'Ticket To The Moon' %%%% <yates@ieee.org> % *Time*, Electric Light Orchestra http://www.digitalsignallabs.com
Reply by ●January 14, 20082008-01-14
> >You check to see if it's available in gnu octave.Randy, I have checked in gnu octave and this is one of the prime reasons for looking out. I have my own library of dsp functions in octave, which help me to do good amount of dsp design work. So I am always on lookout on which functions are missing, and this function happens to be one of them. Bharat Pathak www.arithos.com ~dsp Simplified.
Reply by ●January 15, 20082008-01-15
On 13 Jan., 09:35, "bharat pathak" <bha...@arithos.com> wrote:> Hi, > > � Matlab has a function called iirgrpdelay which helps > � in designing iir group delay equalizer filters. > > � Any idea as to how this function can be re-written > � for people who are not using matlab?Hi Bharat You can use the FDLS method: http://apollo.ee.columbia.edu/spm/external/tipsandtricks/files/TandT_Jan2007.zip Regards, Andor
Reply by ●January 15, 20082008-01-15
>Hi Bharat > >You can use the FDLS method: > >http://apollo.ee.columbia.edu/spm/external/tipsandtricks/files/TandT_Jan2007= >.zip > >Regards, >AndorAndor, Sorry I do not have access to SPM. Regards Bharat Pathak
Reply by ●January 15, 20082008-01-15
On 15 Jan., 14:37, "bharat pathak" <bha...@arithos.com> wrote:> >Hi Bharat > > >You can use the FDLS method: > > >http://apollo.ee.columbia.edu/spm/external/tipsandtricks/files/TandT_... > >.zip > > >Regards, > >Andor > > Andor, > > � �Sorry I do not have access to SPM.The link should be available to everybody (did you try?). I'm sure Greg can send you a copy of the article (else drop me an e-mail).
Reply by ●January 15, 20082008-01-15
On Jan 15, 3:56�am, Andor <andor.bari...@gmail.com> wrote:> You can use the FDLS method:I have an old C-language implementation of FDLS that I could polish-up and make available, if there is enough interest. I've never tried FDLS for phase manipulation, but it should work. Greg Berchin
Reply by ●January 15, 20082008-01-15
Greg Berchin <gberchin@sentientscience.com> wrote in news:91018b6d-0980- 4a7e-aab3-b6816ad7f21c@m34g2000hsb.googlegroups.com:> On Jan 15, 3:56�am, Andor <andor.bari...@gmail.com> wrote: > >> You can use the FDLS method: > > I have an old C-language implementation of FDLS that I could polish-up > and make available, if there is enough interest. > > I've never tried FDLS for phase manipulation, but it should work. > > Greg Berchin >Greg, you're a bit modest. Your FDLS method is very cool. It's described in detail in Streamlining Digital Signal Processing (Rick Lyons new tricks book). I'm sure people would like a polished up C version. I would be glad to include it (or a link) on Danville's signal processing resource page. Al Clark Danville Signal
