search for: parzen

Displaying 10 results from an estimated 10 matches for "parzen".

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2002 Jul 26
0
Parzen Windows
I suspect Prof. Ripley's response suffices. However, there *is* a Parzen kernel for kernel smoothing: Parzen K(z) = { 4/3 - 8z^2 + 8|z|^3 if |z| <= 1/2 8(1 -|z|)^3/3 if 1/2 < |z| <= 1 0 otherwise If I'm not mistaken, this appeared in Parzen's original 1962 paper on kernel density estimation....
2001 Sep 25
1
parzen-window, tukey window
Dear R-user and -programmer, has one R-package the ability to compute smoothed periodograms of time series using the Tukey-window and/or the Parzen-window? In the ts- and tseries-packages I have found only Daniell-smoothers. With many thanks in advance for any hint Albrecht Kauffmann -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send...
2012 Jan 22
1
Problem with sapa package and spectral density function (SDF)
...subdat$yf : subdat$mf > sub.datm <- aggregate(subdat$DA,list(subdat$ymf),mean) > > serie.day <- ts(subdat$DA,start(sub.dat$Year[1],sub.dat$Day[1],frequency=365)) > n.d <- length(serie.day) > espec.day <- SDF(serie.day,method="lag window",window=taper(type="parzen",n.sample=n.d,cutoff=(2*sqrt(n.d))),npad=2*n.d) > > serie.month <- ts(sub.datm,start(sub.dat$Year[1],sub.dat$Month[1]),frequency=12) > n.m<-length(serie.month) > n.m [1] 322 > espec.month<-SDF(serie.month,method="lag window",window=taper(type="parzen&quot...
2024 Jul 10
1
Implementation for selecting lag of a lag window spectral estimator using generalized cross validation (using deviance)
...process. 2. We may compute the periodogram using FFT, for example by the function spectrum in R. 3. The above is badly biased so we taper X_1,...,X_n to reduce the bias in the periodogram. 4. Now that the bias in under control, we focus on reducing the variance. So we take a window like for eg. the Parzen window, and choose a lag length m which controls the amount of smoothing across frequencies. 5. One way of choosing m is mentioned in : https://web.archive.org/web/20080221221221id_/http://www.stat.uiuc.edu/~ombao/PAPERS.dir/gcvbmka.pdf I am looking for an R package which implements 5. Here is a...
2012 Jan 26
2
Calculate a function repeatedly over sections of a ts object
Hi, I want to apply a function (in my case SDF; package ?sapa?) repeatedly over discrete sections of a daily time series object by sliding a time window of constant length (e.g. 10 consecutive years or 1825 days) over the entire ts at increments of 1 time unit (e.g. 1 year or 365 days). So for example, the first SDF would be calculated for the daily values of my variable recorded between years 1
2012 Mar 07
4
Difference in Kaplan-Meier estimates plus CI
...Imagine a simple case with two survival curves (e.g. treatment & control). I just want to calculate the difference in KM estimates at a specific time point (e.g. 1 year) plus the estimate's 95% CI. The former is straightforward, but the estimates not so much. I know methods exist such as Parzen, Wei, and Ying, but was surprised not to find a package that included this. Before I code it up, I thought I'd ask if I was just missing it somewhere. Thank you Jason [[alternative HTML version deleted]]
2009 Nov 23
1
Calibration score for survival probability
...produce what I need (ie a chi-sq type statistic with a table of expected vs observed probabilities). Any other functions I should be aware of? Also, has anybody come across an implementation of the statistic described in: "A global goodness of fit statistic for Cox regression models" by Parzen & Lpisitz, Biometrics 55, 1999 Many thanks in advance Eleni Rapsomaniki Research Associate Strangeways Research Laboratory Department of Public Health and Primary Care University of Cambridge ?
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]]
2002 Jul 26
5
Is there a function for finding local extrema.
I have a vector with about 100.000 values representing a quite regular function (sinusoid like). I would like to find all local maxima of this function (should be about 4000). Is there a native routine for R? Thanks in advance Eryk. -- _|_ \|/ \|/ Eryk Witold Wolski tel :0049-(0)30-8413-1543 w w ?v? 'v? \'v'/ MPI Moleculare Genetik fax :0049-(0)30-8413-1139 |
2012 Mar 25
2
avoiding for loops
I have data that looks like this: > df1 group id 1 red A 2 red B 3 red C 4 blue D 5 blue E 6 blue F I want a list of the groups containing vectors with the ids. I am avoiding subset(), as it is only recommended for interactive use. Here's what I have so far: df1 <- data.frame(group=c("red", "red", "red", "blue",