Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
Hi Alexandre, This is the online tool: http://kmt.hku.nl/~pieter/cgi-bin/resp/nph-PZT.cgi. It starts with an example and every time you refresh the page it gives you a new one. If you scroll down there's a link that tells you how the coefficients were calculated, e.g.: 2 zeros give 3

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Joe White
Hey Alexandre, This blog - EarLevel Engineeringhttp://www.earlevel.com/main/2003/02/28/biquads/ - really helped with my understanding of poles/zeros and biquads. Hope it's useful! Cheers, Joe On 24 September 2013 06:36, Alexandre Torres Porres por...@gmail.comwrote: for what i see, it's not

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
This is the online tool: http://kmt.hku.nl/~pieter/cgi-bin/resp/nph-PZT.cgi. damn, it says it cant load it here :P but this seems like a simple formula to try out, from what you copied here. If that's all, and if I got what it means, I can see a patch coming right now :) let's see! thanks

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
one doubt emerges really soon anyway. Since they are complex (there are two coordinate numbers for each pole and zero) how do I get only one number by, for example, summing or multiplying one pole to the other? as in: *b1* = -(P0 + P1) *b2* = (P0*P1) cheers! 2013/9/24 Alexandre Torres Porres

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
hey joe, this blog is awesome, I stumbled upon it too, they even have an applet that does the job I want, but no code or formulas around :P it's the closest thing I found on the subject in the internet... weird how I can't seem to find these formulas on google and all... cheers 2013/9/24 Joe

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
On Tue, Sep 24, 2013 at 2:36 PM, Alexandre Torres Porres por...@gmail.comwrote: This is the online tool: http://kmt.hku.nl/~pieter/cgi-bin/resp/nph-PZT.cgi. damn, it says it cant load it here :P It doesn't load here either. Perhaps the server is too busy since I put this link here and

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
On Tue, Sep 24, 2013 at 2:50 PM, Alexandre Torres Porres por...@gmail.comwrote: one doubt emerges really soon anyway. Since they are complex (there are two coordinate numbers for each pole and zero) how do I get only one number by, for example, summing or multiplying one pole to the other? as

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
well, not sure what you mean, again way over my head, but I was giving it a hard shot in the dark and it seemed to have worked out :) I just summed both parts of Z0, for instance, and tried the given math, numbers came out! now to make more tests and see if this is consistent, then finish the

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
On Tue, Sep 24, 2013 at 3:08 PM, Funs Seelen funssee...@gmail.com wrote: On Tue, Sep 24, 2013 at 2:50 PM, Alexandre Torres Porres por...@gmail.com wrote: one doubt emerges really soon anyway. Since they are complex (there are two coordinate numbers for each pole and zero) how do I get only

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
so you're basically saying all i need to use is use only the real part, right? my frankenstein was working and alive for several times until i tried some bandpass coeff, let's se if i fix this now :) 2013/9/24 Funs Seelen funssee...@gmail.com On Tue, Sep 24, 2013 at 3:08 PM, Funs Seelen

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
hey, starting to see what you mean much more clear, cool, really excited. Thanks a lot! 2013/9/24 Alexandre Torres Porres por...@gmail.com so you're basically saying all i need to use is use only the real part, right? my frankenstein was working and alive for several times until i tried

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
On Tue, Sep 24, 2013 at 3:35 PM, Alexandre Torres Porres por...@gmail.comwrote: so you're basically saying all i need to use is use only the real part, right? No, I meant that I have the idea that the imaginary part in the calculated coefficients will disappear automatically if you add

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Dan Wilcox
...@gmail.com Subject: Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane) Date: September 24, 2013 12:36:27 AM CDT To: Funs Seelen funssee...@gmail.com Cc: pd-lista puredata pd-list@iem.at for what i see, it's not some sort of straight formula, right

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Alexandre Torres Porres
...@gmail.com *Subject: **Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)* *Date: *September 24, 2013 12:36:27 AM CDT *To: *Funs Seelen funssee...@gmail.com *Cc: *pd-lista puredata pd-list@iem.at for what i see, it's not some sort of straight formula, right

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Simon Wise
On 24/09/13 21:46, Funs Seelen wrote: On Tue, Sep 24, 2013 at 3:35 PM, Alexandre Torres Porres por...@gmail.comwrote: so you're basically saying all i need to use is use only the real part, right? No, I meant that I have the idea that the imaginary part in the calculated coefficients will

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
On Tue, Sep 24, 2013 at 6:32 PM, Simon Wise simonzw...@gmail.com wrote: On 24/09/13 21:46, Funs Seelen wrote: On Tue, Sep 24, 2013 at 3:35 PM, Alexandre Torres Porres por...@gmail.comwrote: so you're basically saying all i need to use is use only the real part, right? No, I meant that

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-24 Thread Funs Seelen
On Tue, Sep 24, 2013 at 6:13 PM, Alexandre Torres Porres por...@gmail.comwrote: after some shots in the dark, adjustments and stuff, I was able to make it work really well... thanks a lot again, will put this out hopefully soon after I clean it up and include some features. Cheers Great!

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-23 Thread Funs Seelen
Hi Alexandre, Great that you're doing this! For extra inspiration you could have a look at PoZeTools (http://kmt.hku.nl/~pieter/SOFT/RESP/html/PoZeTools.html). It's great software by Pieter Suurmond. He's the one who taught me filter design and he probably has some info about Z-transform on his

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-23 Thread Funs Seelen
On Mon, Sep 23, 2013 at 5:35 PM, Alexandre Torres Porres por...@gmail.comwrote: thanks, here's a pic of what I have so far https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-prn1/11212_10151872996046683_1825736206_n.jpg Cool. For extra inspiration you could have a look at PoZeTools

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-23 Thread Alexandre Torres Porres
Great that you're doing this! thanks, here's a pic of what I have so far https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-prn1/11212_10151872996046683_1825736206_n.jpg For extra inspiration you could have a look at PoZeTools It sure does look like what I need. Thanks. But extracting what I

Re: [PD] from poles/zeros to biquad coefficients - how to? (something like max's z-plane)

2013-09-23 Thread Alexandre Torres Porres
for what i see, it's not some sort of straight formula, right? seems a bit more complicated than that. cheers 2013/9/23 Funs Seelen funssee...@gmail.com On Mon, Sep 23, 2013 at 5:35 PM, Alexandre Torres Porres por...@gmail.com wrote: thanks, here's a pic of what I have so far