similar to: Spectral analysis

Displaying 20 results from an estimated 1000 matches similar to: "Spectral analysis"

2008 Dec 03
2
Spectral Analysis of Time Series in R
Dear R Community, I am currently student at the Vienna University of Technology writing my Diploma thesis on causality in time series and doing some analyses of time series in R. I have the following questions: (1) Is there a function in R to estimate the PARTIAL spectral coherence of a multivariate time series? If yes, how does this work? Is there an test in R if the partial spectral
2002 Oct 22
3
Spectral phase information in residue vectors
I found this sentence in the Ogg format specs: http://www.xiph.org/ogg/vorbis/doc/vorbis-spec-res.html "A residue vector may represent spectral lines, spectral magnitude, spectral phase or hybrids as mixed by channel coupling." But where does the spectral phase information come from ? AFAIK MDCT doesn't provide any phase information. And in OGG-encoding, MDCT is taking place a few
2008 Mar 27
6
help! - spectral analysis - spec.pgram
Can someone explain me this spec.pgram effect? Code: period.6<-c(0,0,0,0,0,10,0,0,0,0,0,10,0,0,0,0,0,10,0,0,0,0,0,10,0,0,0,0,0,10 ,0,0,0,0,0,10,0,0,0,0,0,10,0,0,0,0,0,10,0,0,0,0,0,10,0,0,0,0,0,10) period.5<-c(0,0,0,0,0,10,0,0,0,0,10,0,0,0,0,0,0,10,0,0,0,0,10,0,0,0,0,0,0,10 ,0,0,0,0,10,0,0,0,0,0,0,10,0,0,0,0,10,0,0,0,0,0,0,10,0,0,0,0,10,0) par(mfrow=c(2,1))
2003 Mar 24
1
wavelet model on time series in R?
Hello, Is there package built for R that can do model/prediction on time series data using wavelet? If not, does anyone know what popular software can do that? Thanks much, yan
2009 Mar 23
1
how to estimate multidimensional spectral measure of coherence
Please, does anyone know of an R packge to estimate multidimensional spectral measure of coherence within a moving time window ? Some time ago I expeimented with a similar package that performs Cross Spectrum Analysis on the whole signal though. Unluckily I deal with non-stationary signals whose properties change along with time. Therefore estimates can only be made over time periods roughly
2006 Jan 27
2
How do I "normalise" a power spectral density analysis?
Hi everyone Can anyone tell me how I normalise a power spectral density (PSD) plot of a periodical time-series. At present I get the graphical output of spectrum VS frequency. What I want to acheive is period VS spectrum? Are these the same things but the x-axis scale needs transformed ? Any help would be greatly appreciated Tom
2007 Jan 08
2
Simple spectral analysis
Hello world, I am actually trying to transfer a lecture from Statistica to R and I ran into problems with spectral analysis, I think I just don't get it 8-( (The posting from "FFT, frequs, magnitudes, phases" from 2005 did not enlighten me) As a starter for the students I have a 10year data set of air temperature with daily values and I try to get a periodogram where the annual
2011 Jul 11
1
Spectral Coherence
Greetings, I would like to estimate a spectral coherence between two timeseries. The stats : spectrum() returns a coh matrix which estimates coherence (squared). A basic test which from which i expect near-zero coherence: x = rnorm(500) y = rnorm(500) xts = ts(x, frequency = 10) yts = ts(y, frequency = 10) gxy = spectrum( cbind( xts, yts ) ) plot( gxy $ freq, gxy $
2006 Jan 08
2
Filters in waveslim
Dear R Users, For running wavelet functions using dwt( ), modwt( ), and mra( ), a wavelet filter algorithm is applied. For all these functions, default is "la8" and other possibility is "haar". In related documents, another possibilities like as symlet and coiflet ... are not cited. Besides "la8" and "haar", which wavelet filters can be used? Thank
2003 Feb 25
1
Wavelets correlation test
Hello, I use wavethresh packages to perform wavelet analysis. In particular, I would like to compare 2 signals (vectors) after a wavelet decomposition. I would like to use cor.test function, but this function acts on the entire vector values. I plan to perform a cor.test on each level of the wavelet decomposition, say N. So I will have at the end of a first step N results of cor.test. How can
2004 Jan 21
1
Mac OS X and R
My Windows machine has gone "kaput" and I am trying to see how R might work on my Mac. I am interested in using the contributed packages, especially "waveslim" and "wavethresh". Are all packages available under either Windows, Mac, or Unix? I can't seem to tell from the documentation whether this is so (probably because I am not very computer literate!). Any
2010 Sep 28
1
Best package for time series analysis with wavelets???
Hi!! I'm looking for a package in R for time series analysis using wavelets( I'm interested on extractingt information from electrocardiograms with the aim of study the heart rate variability) so i want to know which package is the best for me. I've thinking about using some of those(you can recommend me others,xD): *wavelets: A package of funtions for computing wavelet filters,
2006 Jan 31
1
How do I "normalise" a power spectral density
I have done a fair bit of spectral analysis, and hadn't finished collecting my thoughts for a reply, so hadn't replied yet. What exactly do you mean by normalize? I have not used the functons periodogram or spectrum, however from the description for periodogram it appears that it returns the spectral density, which is already normalized by frequency, so you don't have to worry about
2018 Apr 10
2
Spectral analisys for for R version 3.4.3
Dear all, Is there any spectral analisys functionality available for R version 3.4.3? Series() functionality doesn't work in this version. Regards Danniel [[alternative HTML version deleted]]
2003 Jul 03
2
SVD and spectral decompositions of a hermitian matrix
Hi: I create a hermitian matrix and then perform its singular value decomposition. But when I put it back, I don't get the original hermitian matrix. I am having the same problem with spectral value decomposition as well. I am using R 1.7.0 on Windows. Here is my code: X <- matrix(rnorm(16)+1i*rnorm(16),4) X <- X + t(X) X[upper.tri(X)] <- Conj(X[upper.tri(X)]) Y <-
2007 Jun 29
2
Spectral Decomposition
All of my resources for numerical analysis show that the spectral decomposition is A = CBC' Where C are the eigenvectors and B is a diagonal matrix of eigen values. Now, using the eigen function in R # Original matrix aa <- matrix(c(1,-1,-1,1), ncol=2) ss <- eigen(aa) # This results yields back the original matrix according to the formula above ss$vectors %*% diag(ss$values) %*%
2002 Oct 27
1
denoising univariate data with wavelets
Hi, I am interested in a applying wavelets as a smoothing tool for my (1-dimensional) data. I looked into wavetresh and waveslim packages but could not quite figure out an obvious way to do this after running dwt or wt functions. Would someone be able to point me in the right direction on how to denoise univariate data using one of wavelet packages available in R? Thank you very much Jane ps
2006 May 25
3
Wavelet Functions
Does R have any wavelet functions? When I type > help.search("wavelet") I get " No help files found with alias or concept or title matching 'wavelet' using fuzzy matching." Thanks, Peter.
2012 Oct 23
1
find similarity between two spectral profile
Hi, I'm Pina and I'm a student in geology. I'm working with spectral profile of sand and I have to find the similarity between one spectral profile selected by hyperspectral image anche one that I created to mix different percentage of 4 mineral component. I have to find the best mix of percentage of this 4 mineral in order to have the best likeness with the spectral profile chose by
2009 Oct 11
2
spectral analysis
Dear all, I am searching the period of a time series usering R. Is there some lag window functions in R? Could you give me some books about spectral analysis usering R? best wishes, Wang [[alternative HTML version deleted]]