[R] deconvolution: Using the output and a IRF to get the input
Hi, Maybe someone could give me some pointers for my problem. So far I have not found a good solution, maybe it is just ill posed? I have a signal that is the result of an input signal convolved with a given impulse response function (IRF) plus noise. I want to use the this signal and the IRF to determine the underlying input signal. In my naivety I thought this just might be a deconvolution problem. But here I found only routines that use the input signal and the output signal to get the IRF. Is it possible to derive the input signal when output and IRF are given? If so, how could I do this with R? Thanks a lot for any hints, wolf __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] deconvolution: Using the output and a IRF to get the input
Hi Wolf, Without noise you could use FFT, i.e. FFT of a convolution is the product of the individual FFTs and so you get the FFT of your input signal and using inverse FFT you get the signal itself. When there is noise you must experiment. You may want to filter the response before doing FFT. Whay do you know about the noise? Regards, Moshe. --- On Mon, 25/8/08, wolf zinke [EMAIL PROTECTED] wrote: From: wolf zinke [EMAIL PROTECTED] Subject: [R] deconvolution: Using the output and a IRF to get the input To: r-help@r-project.org Received: Monday, 25 August, 2008, 8:22 AM Hi, Maybe someone could give me some pointers for my problem. So far I have not found a good solution, maybe it is just ill posed? I have a signal that is the result of an input signal convolved with a given impulse response function (IRF) plus noise. I want to use the this signal and the IRF to determine the underlying input signal. In my naivety I thought this just might be a deconvolution problem. But here I found only routines that use the input signal and the output signal to get the IRF. Is it possible to derive the input signal when output and IRF are given? If so, how could I do this with R? Thanks a lot for any hints, wolf __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] deconvolution: Using the output and a IRF to get the input
remember the the inverse of fft has to be divided by the number of observations. On Sun, Aug 24, 2008 at 8:35 PM, Moshe Olshansky [EMAIL PROTECTED] wrote: Hi Wolf, Without noise you could use FFT, i.e. FFT of a convolution is the product of the individual FFTs and so you get the FFT of your input signal and using inverse FFT you get the signal itself. When there is noise you must experiment. You may want to filter the response before doing FFT. Whay do you know about the noise? Regards, Moshe. --- On Mon, 25/8/08, wolf zinke [EMAIL PROTECTED] wrote: From: wolf zinke [EMAIL PROTECTED] Subject: [R] deconvolution: Using the output and a IRF to get the input To: r-help@r-project.org Received: Monday, 25 August, 2008, 8:22 AM Hi, Maybe someone could give me some pointers for my problem. So far I have not found a good solution, maybe it is just ill posed? I have a signal that is the result of an input signal convolved with a given impulse response function (IRF) plus noise. I want to use the this signal and the IRF to determine the underlying input signal. In my naivety I thought this just might be a deconvolution problem. But here I found only routines that use the input signal and the output signal to get the IRF. Is it possible to derive the input signal when output and IRF are given? If so, how could I do this with R? Thanks a lot for any hints, wolf __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Stephen Sefick Research Scientist Southeastern Natural Sciences Academy Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us feel like gods. We are mammals, and have not exhausted the annoying little problems of being mammals. -K. Mullis __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
