search for: spectral

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 coherence between two variables is zero? The functions I know (spectrum, etc.) only work to estimate the spectral coherence. (2) For some causality analysis I need an estimate of...

Dear list, i would like to build an own package using: R CMD INSTALL --html --build --auto-zip -l folder spectral.methods it seems to succeed as I get the following messages: * installing *source* package 'spectral.methods' ... ** R ** data Warning: empty 'data' directory ** preparing package for lazy loading ** help *** installing help indices converting help for package 'spectral.meth...

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 steps before computing the residue vectors. &lt...

Hi all, I am dealing with paleoceanographic data and I have a C14 time serie and one other variable. I would like to perform a spectral analysis (fft or wavelet) and plot it. Unfortunately I don't know the exact script to do this. Does anybody could send me an example to perform my spectral analysis ? I Thank you David Changez de tête et de tenue tous les jours si vous le voulez ! Volez la vedette sur Yahoo! Québec Av...

I used the AR modelling written for R (S) on blood pressure and heart rate signals. I used 60 one second samples and a model order of 20. I used the "ar" finction in the "ts" package. Given that blood pressure is measured in mmHg would the spectral density (on the graph displayed be [mmHg]sq/Hz ? And the heart rate is measured in Beats Per Minute (bpm) - so would the displayed spectral density be in (bpm)sq/Hz ? I'm sorry if this seems a trivial question, however the resultant values seem inconsistent with published data (although the s...

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 alr...

...to R and looking for a way to use a variable to reference to an object. I'm plotting several graphs on top of each other and want to do this by a for loop. The field I want to graph have names like a1,a2,a3, ... I can't figure out how to get this working: It should look like this: lines(spectral$Wavelength,paste("spectral$a",j,sep=""),col=j) but the "paste()" does not seem to work in this context. Any help? Kind regards, Kris -- ------------------------------------------------------------------------ http://perswww.kuleuven.ac.be/~u0027178/VCard/mycar...

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))

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...

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 spectra...

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 ................................

Dear collegues, I´ ve worked with near infrared (NIR) spectroscopy to assess chemical, physical, mechanical and anatomical properties of wood. I use "The Unscrambler" software to correlate the matrix of dependent variables (Y) with the matrix of spectral data (X) and I would like to migrate to R. The matrix of spectral variables is very large (2345 columns and n lines, where n = samples), so we used Partial Least Squares Regression to predict a variable y (content of cellulose, for instance) based on the spectral variables, which are the NIR wavele...

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 period (365 days...

...random stationary signal of gaussian probability density function to simulate narrow band noise at the output of an IF amplifier. I know the receiver's system temperature (Ts) and IF bandwidth (B) therefore I assume that my narrow band noise mean power equals KTsB watts and therefore the power spectral density No=KTs per Hz. Do you know any relationship between No and sigma^2 so I can simulate the stationary random signal in matlab? Theory says that for white noise No/2=sigma^2 but this formula I believe is only valid for white broadband noise. I will appreciate your opinion. Regards Dim Patridg...

I compared quicktime aac and vorbis,i think quicktime aac is better than vorbis at 80Kbps. please tell me if i'm wrong. using command: qtaacenc.exe --tvbr 31 --highest --samplerate keep test.wav qt.m4a oggenc2.exe --raw -q 1.6 test.wav -o vorbis.ogg the version: qtaacenc version 20100725 with QuickTime 7.6.7 OggEnc v2.87 (libvorbis 1.3.1) links:

Hello! I would like to ask if there is in R a function that estimates the spectral density function of a stochastic series at frequency zero by the "plug-in method", advocated by Andrews in his paper "Heteroscedasticity and Autocorrelation Consistent Covariance Matrix Estimation", Econometrica, 59,817-858. I saw R has functions that employ Andrews' plug-in...

Hello all, I would like to use the train function from the caret package to train a svm with a spectral kernel from the kernlab package. Sadly a svm with spectral kernel is not among the many methods in caret... using caret to train svmRadial: ------------------ library(caret) library(kernlab) data(iris) TrainData<- iris[,1:4] TrainClasses<- iris[,5] set.seed(2) fitControl$summaryFunction&lt...

Greetings, I'm working on image classification and for that I want to use the spectral slope as a feature for my classifier. For this I would prefer to calculate this feature using R, so far I've read my image and converted it's RGB representation into HSL. The spectral slope is computed over the Luminance component, so at the moment what I have is a NxN matrix of Luminance v...

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]]

Dear sirs, My name is Marcelo Grimaldi and i work for General Electric in the Six Sigma Program. Recently I became very interested in spectral analysis, because I think it can be applied to my job. I use Minitab 12 and i have heard that writing macros for spectral analysis in this software is very difficult. Could I perform this analysis in a easier way throught "R" ? Have you ever heard about anybody that perform it using &quot...