Hi, I'm currently looking for a PC software library that can be used to dynamically design IIR filters such as Butterworth, Chebychev, Elliptic ... I can't find something that is very well kown. I'm astonished that there is no (or very few) popular libraries to face such a common problem. Does somebody know such a library ? The libray I'm looking for should : - provide routines able to provide IIR filters coefficients from high level specifications (filter type, order, transition bands, bandpass and bandstop ripple ...) - be well known and/or supported by a reliable company/group - be used, tested and validated by numerous users - have an interface for Delphi, but I can also deal with C or C++ - be shipped with a extensive set of test routines - be as cheap as possible, but this is not the main point Thank you for your inputs Olivier Cochelin Notocord Systems
IIR filter design libray
Started by ●January 19, 2005
Reply by ●January 19, 20052005-01-19
Hi! www.dewresearch.com If you can find something better let me know <g> Regards! Atmapuri "CoCo" <coco_corp@yahoo.fr> wrote in message news:af247ee9.0501190017.28cf75ea@posting.google.com...> Hi, > > I'm currently looking for a PC software library that can be used to > dynamically design IIR filters such as Butterworth, Chebychev, > Elliptic ... > > I can't find something that is very well kown. I'm astonished that > there is no (or very few) popular libraries to face such a common > problem. Does somebody know such a library ? > > The libray I'm looking for should : > - provide routines able to provide IIR filters coefficients from high > level specifications (filter type, order, transition bands, bandpass > and bandstop ripple ...) > - be well known and/or supported by a reliable company/group > - be used, tested and validated by numerous users > - have an interface for Delphi, but I can also deal with C or C++ > - be shipped with a extensive set of test routines > - be as cheap as possible, but this is not the main point > > Thank you for your inputs > > > Olivier Cochelin > Notocord Systems
Reply by ●January 19, 20052005-01-19
coco_corp@yahoo.fr (CoCo) wrote in news:af247ee9.0501190017.28cf75ea@posting.google.com:> Hi, > > I'm currently looking for a PC software library that can be used to > dynamically design IIR filters such as Butterworth, Chebychev, > Elliptic ... > > I can't find something that is very well kown. I'm astonished that > there is no (or very few) popular libraries to face such a common > problem. Does somebody know such a library ? > > The libray I'm looking for should : > - provide routines able to provide IIR filters coefficients from high > level specifications (filter type, order, transition bands, bandpass > and bandstop ripple ...) > - be well known and/or supported by a reliable company/group > - be used, tested and validated by numerous users > - have an interface for Delphi, but I can also deal with C or C++ > - be shipped with a extensive set of test routines > - be as cheap as possible, but this is not the main point > > Thank you for your inputs > > > Olivier Cochelin > Notocord SystemsI have used a program from Momentum Data Systems for many years called QEDesign. It is very good at creating filter coefficient files. It might work for your application. www.mds.com -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- Purveyors of Fine DSP Hardware and other Cool Stuff Available at http://www.danvillesignal.com
Reply by ●January 19, 20052005-01-19
CoCo wrote:> > Hi, > > I'm currently looking for a PC software library that can be used to > dynamically design IIR filters such as Butterworth, Chebychev, > Elliptic ...ON Linux you could try http://www.watri.org.au/~ajh/libfilth/ It may not be pssible to get it to compile on windows. Erik -- +-----------------------------------------------------------+ Erik de Castro Lopo nospam@mega-nerd.com (Yes it's valid) +-----------------------------------------------------------+ "Cunnilinugus and psychiatry brought us to this." -- Tony Soprano in HBO's "the Sopranos"
Reply by ●January 19, 20052005-01-19
ONEoverT is a good package. I seem to recall that Tyder were selling a DSP library at one time. Bob CoCo wrote:> Hi, > > I'm currently looking for a PC software library that can be used to > dynamically design IIR filters such as Butterworth, Chebychev, > Elliptic ... > > I can't find something that is very well kown. I'm astonished that > there is no (or very few) popular libraries to face such a common > problem. Does somebody know such a library ? > > The libray I'm looking for should : > - provide routines able to provide IIR filters coefficients from high > level specifications (filter type, order, transition bands, bandpass > and bandstop ripple ...) > - be well known and/or supported by a reliable company/group > - be used, tested and validated by numerous users > - have an interface for Delphi, but I can also deal with C or C++ > - be shipped with a extensive set of test routines > - be as cheap as possible, but this is not the main point > > Thank you for your inputs > > > Olivier Cochelin > Notocord Systems
Reply by ●January 21, 20052005-01-21
Thanks for the link Erik. The manual is a good overview of a lot of filter design techniques. Cheers, Syms. p.s. Going down your post, it's spelt 'Cunnilingus'! ;-) "Erik de Castro Lopo" <nospam@mega-nerd.com> wrote in message news:41EEC16E.8C127D52@mega-nerd.com...> > ON Linux you could try > > http://www.watri.org.au/~ajh/libfilth/ > > It may not be pssible to get it to compile on windows. > > Erik > -- > +-----------------------------------------------------------+ > Erik de Castro Lopo nospam@mega-nerd.com (Yes it's valid) > +-----------------------------------------------------------+ > "Cunnilinugus and psychiatry brought us to this." > -- Tony Soprano in HBO's "the Sopranos"
Reply by ●February 10, 20052005-02-10
Many thanks to all of you. Your proposals were useful. Just to make things clearer, what I'm looking for is a software library that can be called from code of my own. Indeed, in my application, filters need to be design dynamically to meet user requirements. Stand alone software that can be used to design filters (such as Matlab does for example) is not a suitable solution for me. Wide usage and good support of the library is a key point. Olivier Cochelin Notocord Systems
Reply by ●March 1, 20052005-03-01
Making adjustable IIR filters is tricky. Depending on adjustments, the filters may transition through an unstable region with unpredictable results. This problem doesn't exist with FIR filters. I have done something similar using a FIR filter and the Parks-McClellan algorithm. Worked for a three kHz bandwith in real time. In article <af247ee9.0502101004.2010fa60@posting.google.com>, coco_corp@yahoo.fr (CoCo) wrote:>Many thanks to all of you. Your proposals were useful. > >Just to make things clearer, what I'm looking for is a software >library that can be called from code of my own. Indeed, in my >application, filters need to be design dynamically to meet user >requirements. >Stand alone software that can be used to design filters (such as >Matlab does for example) is not a suitable solution for me. > >Wide usage and good support of the library is a key point. > > >Olivier Cochelin >Notocord Systems
Reply by ●March 1, 20052005-03-01
in article D0SUd.15651$VD5.13664@twister.socal.rr.com, George Bush at george.w.bush@whitehouse.com wrote on 02/28/2005 23:16:> Making adjustable IIR filters is tricky. Depending on adjustments, the > filters may transition through an unstable region with unpredictable results.not for Direct Form 1 or Direct Form 2 or Lattice or Normalized Ladder, or the Gold-Rader architectures. unless there is overshoot in the coefficient slewing (which won't happen for linear slewing nor for 1st order LPF slewing), even as the denominator coefficients are slewed from one stable value to another, *none* of the values in between are unstable. this has been discussed before, but it was so long ago that i wouldn't know where to begin Googling. now E-mu's Dave Rossum (or maybe it was Jean Larouche) did a paper that there is temporary instability in some cases due to the movement of the coefficients. but any static value in between stable endpoints is stable. -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
Reply by ●March 3, 20052005-03-03
CoCo wrote:> Many thanks to all of you. Your proposals were useful. > > Just to make things clearer, what I'm looking for is a software > library that can be called from code of my own. Indeed, in my > application, filters need to be design dynamically to meet user > requirements. > Stand alone software that can be used to design filters (such as > Matlab does for example) is not a suitable solution for me.Along the same lines -- does anyone know where to find algorithms for numerically transforming LP IIR prototypes into highpass, bandpass and bandstop filters? I don't want packages that do the job for me, I want to be able write my own package. Rune
