Displaying 20 results from an estimated 3000 matches similar to: "Documentation for taper in spec.taper (PR#8871)"
2024 Jul 10
1
Implementation for selecting lag of a lag window spectral estimator using generalized cross validation (using deviance)
Dear All,
I am looking for:
A software to select the lag length for a lag window spectral estimator.
Also, I have a small query in the reprex given below.
Background for the above, from the book by Percival and Walden:
1. We are given X_1,...,X_n which is one realization of a stochastic process.
2. We may compute the periodogram using FFT, for example by the
function spectrum in R.
3. The
2009 Jun 19
1
typo in Lomb-Scargle periodogram implementation in spec.ls() from cts package?
Hello!
I tried to contact author of the package, but I got no reply. That is why I write it here. This might be useful for those who were using cts for spectral analysis of non-uniformly spaced data.
In file spec.ls.R from cts_1.0-1.tar.gz lines 59-60 are written as
pgram[k, i, j] <- 0.5 * ((sum(x[1:length(ti)]* cos(2 * pi * freq.temp[k] * (ti - tao))))^2/sum((cos(2 *
pi * freq.temp[k] *
2008 Jun 09
2
using spec.pgram
Hi everyone,
first of all, I would like to say that I am a newbie in R, so I apologize in
advance if my questions seem to be too easy for you.
Well, I'm looking for periodicity in histograms. I have histograms of
certain phenomenons and I'm asking whether a periodicity exists in these
data. So, I make a periodogram with the function spec.pgram. For instance,
if I have a histogram h, I
2007 Dec 12
2
discrepancy between periodogram implementations ? per and spec.pgram
hello,
I have been using the per function in package longmemo to obtain a
simple raw periodogram.
I am considering to switch to the function spec.pgram since I want to be
able to do tapering.
To compare both I used spec.pgram with the options as suggested in the
documentation of per {longmemo} to make them correspond.
Now I have found on a variety of examples that there is a shift between
2007 Nov 25
1
spec.pgram() - circularity of kernel
Hi,
I am far from experienced in both R and time series hence the question.
The code for spec.pgram() seems to involve a circularity of the kernel (see
below) yielding new power estimates to all frequencies computed by FFT.
"
if (!is.null(kernel)) {
for (i in 1:ncol(x)) for (j in 1:ncol(x)) pgram[, i,
j] <- kernapply(pgram[, i, j], kernel, circular = TRUE)
2004 Sep 20
1
unable to load shared library "/home/hpc1367/runs/taper/taper.so"
I am trying to load a .so file and get the following error message:
> dyn.load("taper.so",local=F)
Error in dyn.load(x, as.logical(local), as.logical(now)) :
unable to load shared library
"/home/hpc1367/runs/taper/taper.so":
ld.so.1: /usr/local/lib/R/bin/R.bin: fatal: relocation error: file
/home/hpc1367/runs/taper/taper.so: symbol f90_init: referenced symbol
not
2020 Oct 19
1
spec.pgram returns different spectra when fast=TRUE and the number of samples is odd
Dear all,
This is potentially a bug in spec.pgram, when the number of samples is odd,spec.pgramreturns a different result withfast = TRUE, the example below contains the two varieties with a reference spectrum calculated manually. the number of returned spectra is also larger (50 compared to 49) whenfast = TRUE
x <- rnorm(
99
)
plot(spec.pgram(x, taper =
0
, detrend =
FALSE
, plot =
2019 Feb 14
0
Proposed speedup of spec.pgram from spectrum.R
Hello,
I propose two small changes to spec.pgram to get modest speedup when
dealing with input (x) having multiple columns. With plot = FALSE, I
commonly see ~10-20% speedup, for a two column input matrix and the speedup
increases for more columns with a maximum close to 45%. In the function as
it currently exists, only the upper right triangle of pgram is necessary
and pgram is not returned by
2008 Apr 19
1
Inverse transform after applying function in frequency domain?
Dear R-Help,
I wish to simulate a process so that it has certain properties in the
frequency domain. What I attempted was to generate a random time-series
signal, use spec-pgram(), apply a function in the frequency domain, and then
inverse transform back to the time-domain. This idea does not seem as
straight forward in practice as I anticipated.
e.g.
x<-ts(rnorm(1000, 0,1), frequency=256)
2006 Jan 24
1
spec.pgram() normalized too what?
Dear list,
What on earth is spec.pgram() normalized too? If you would like to skip my
proof as to why it's not normed too the mean squared or sum squared
amplitude of the discrete function a[], feel free too skip the rest of the
message. If it is, but you know why it's not exact in spec.pgram() when it
should be, skip the rest of this message. The issue I refer herein refers
only too a
2006 Jan 24
3
R-help Digest, Vol 35, Issue 24
Dear Prof Ripley,
First of all, unless you are an english professor, then I do not think you have
any business policing language. I'm still very much a student, both in R, and
regarding signal analysis. My competence on the subject as compared too your
own level of expertise, or my spelling for that matter, may be a contension for
you, but it would have been better had you kept that opinion
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))
2004 Oct 15
1
power in a specific frequency band
Dear R users
I have a really simple question (hoping for a really simple answer :-):
Having estimated the spectral density of a time series "x" (heart rate
data) with:
x.pgram <- spectrum(x,method="pgram")
I would like to compute the power in a specific energy band.
Assuming that frequency(x)=4 (Hz), and that I am interested in the band
between f1 and f2, is the
1999 Jul 19
9
time series in R
Time Series functions in R
==========================
I think a good basic S-like functionality for library(ts) in base R
would include
ts class, tsp, is.ts, as.ts
plot methods
start end window frequency cycle deltat
lag diff aggregate
filter
spectrum, spec.pgram, spec.taper, cumulative periodogram, spec.ar?
ar -- at least univariate by Yule-Walker
arima -- sim, filter, mle, diag, forecast
2009 Jan 26
0
Spectral analysis with mtm-svd Multi-Taper Method Combined with Singular Value Decomposition
Hi list,
Does anyone know if there is a library in R that does MTM-SVD method for
spectral analysis?
Thanks
-----
Yasir H. Kaheil
Columbia University
--
View this message in context: http://www.nabble.com/Spectral-analysis-with-mtm-svd-Multi-Taper-Method-Combined-with-Singular-Value-Decomposition-tp21671934p21671934.html
Sent from the R help mailing list archive at Nabble.com.
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
2008 Sep 09
4
Help with 'spectrum'
For the command 'spectrum' I read:
The spectrum here is defined with scaling 1/frequency(x), following S-PLUS. This makes the spectral density a density over the range (-frequency(x)/2, +frequency(x)/2], whereas a more common scaling is 2? and range (-0.5, 0.5] (e.g., Bloomfield) or 1 and range (-?, ?].
Forgive my ignorance but I am having a hard time interpreting this. Does this mean
1999 Jul 27
3
Preliminary version of ts package
There is now a preliminary version of a time series package in the R-devel
snapshots, and we would welcome feedback on it. It is based in part on the
packages bats (Martyn Plummer) and tseries (Adrian Trapletti) and in part
on code I had or have written. (Thanks for the contributions, Martyn and
Adrian!) Some of the existing ts code has been changed, for example to plot
multiple time series, so
2012 Apr 02
2
Reading first line before using read.table()
So far I have figured out that the following line
reads our time series files into R OK.
dtLs$dta <- read.table("C:/TryRRead/datFiles/JFeqfi4h.rta", header = TRUE,
sep = ",", colClasses = "character")
But I have to remove a main-title line so
that the first line is the column titles line.
This leads to having two sets of data files around when
we would rather
1999 Dec 01
1
density(kernel = "cosine") .. the `wrong cosine' ..
I'm in teaching mode, kernel densities.
{History: density() was newly introduced in version 0.15, 19 Dec 1996;
most probably by Ross or Robert
}
When I was telling the students about different kernels (and why their
choice is not so important, and "equivalent bandwidths" etc,etc)
I wondered about the "Cosine" in my teaching notes which
is defined there as
k(x)