Displaying 20 results from an estimated 10000 matches similar to: "Sort (indices only)"
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
2009 Jan 14
3
Partial sort?
This is definitely a newbie question but from the documentation I have not been able to figure out what the partial sort option on the sort method does. I have read and re-read the documentation and looked at the examples but for some reason it doesn't register. Would someone attempt to explain what sort with a non-null partial array of indices does?
Thank you.
Kevin
2008 Oct 07
4
sort a list?
I am trying to sort a list and the data is obiously not in the right format. I am trying:
x <- list()
x[["A"]] <- 1
x[["B"]] <- 2
order(x)
But am getting:
Error in order(x) : unimplemented type 'list' in 'orderVector1'
How should I change the list so that it can be sorted? What kinds of objects (classes of objects) can be sorted?
Thank you.
Kevin
2008 Sep 04
1
Building a time series.
I have a need to build a time series and there are a couple of aspects about the time series object that are confusing me. First it seems that ts.union is not doing what I would expect. For example:
x0 <- rep(0,10)
x1 <- rep(1,10)
xt0 <- ts(x0, frequency=10)
xt1 <- ts(x1, frequency=10)
st2 <- ts.union(xt0, xt1)
> xt2
Time Series:
Start = c(1, 1)
End = c(1, 10)
Frequency = 10
2010 Mar 06
1
Interpretation of 'swtich'
In browsing the source I see the following construct:
res <- switch(type, working = , response = r, deviance = ,
pearson = if (is.null(object$weights))
r
else r * sqrt(object$weights), partial = r)
I understand that 'switch' will execute the code that is matched by its corresponding string value (in this case 'type'). What I don't
2009 Apr 03
4
embed?
I have a question on the function 'embed'. I ran the example
x <- 1:10
embed(x, dimension=3)
This gives the output:
[,1] [,2] [,3]
[1,] 3 2 1
[2,] 4 3 2
[3,] 5 4 3
[4,] 6 5 4
[5,] 7 6 5
[6,] 8 7 6
[7,] 9 8 7
[8,] 10 9 8
I don't quite understand the output and why it is useful. First, there are only 8
2011 Oct 22
7
"Plotting" text?
I noticed that the text() command adds text to a plot. Is there a way to
either make the plot blank or add text to a "blank sheet". I would like
to "plot" a page that contains just text, no plot lines, labels, etc.
Suggestions?
Kevin
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2006 Feb 01
2
VFS audit
I would like to turn on auditing for a particular share and have all
auditing go to the username.machinename.log files. If I turn on audit
then no matter which way I configure it, it either goes to just syslog,
or both. My goal is to just log to the samba files and take the wieght
off of syslog. I have searched and searched but can't find but a
solution that works. Any help would be
2008 Oct 10
2
Leap year?
Given a Date object or simply a year is there an R function to tell me if the it is a leap year or not? I was hoping for something like 'is.leapyear'. I probably can build my own function (year divisible by 4 etc.) but I would rather use an existing function if it is available.
Thank you.
Kevin
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
2008 Aug 28
6
Function not returning a vector?
Why does:
(shape/scale) * (1:365/scale)^(shape - 1)
return a vector of numbers but calling a function
hasard(1:365,shape,scale)
defined like:
hazard <- function(x,shape,scale)
{
return (shape/scale) * (x/scale)^(shape - 1)
}
Only return a single value? It is like x becomes a single value passed as an argument.
Thank you.
Kevin
2009 Jan 03
5
Power functions?
I had a question about the basic power functions in R.
For example from the R console I enter:
-1 ^ 2
[1] -1
but also
-1^3
[1] -1
-0.1^2
[1] -0.01
Normally pow(-1, 2) return either -Infinity or NaN. Has R taken over the math functions? If so I would think that -1^2 is 1 not -1 and -0.1^2 is 0.01 not -0.01.
Thank you.
Kevin
2010 Mar 22
2
Factors attribute?
I noticed that when I fit a linear model using 'lm' there is an attribute called "factors" that is added to the "term". It doesn't seem to appear for 'model.matrix', just 'lm'. I have been unable to find where it gets constructed or what it means? It looks like a two dimensional array that I may be able to use so I would just like to get some
2004 Jan 22
1
spectrum
Dear R users
I have two questions about estimating the spectral power of a
time series:
1) I came across a funny thing with the following code:
data(co2)
par(mfrow=c(2,1))
co2.sp1<-spectrum(co2,detrend=T,demean=T,span=3)
co2.sp2<-spectrum(co2[1:468],detrend=T,demean=T,span=3)
The first plot displays the frequencies ranging from 0 to 6
whearas the second plot displays the same curve but
2011 Nov 07
3
Upgrade R?
I am trying to upgrade to R 2.14 from R 2.13.1 I have compied all the
libraries from the 'library' directory in my existing installation (2.13.1)
to the installed R 2.14. Now I want to uninstall the old installation (R
2.13.1) and I get the error:
Internal Error: Cannot find utCompiledCode record for this version of the
uninstaller.
Any ideas?
Kevin
[[alternative HTML
2007 Dec 19
4
Factor Madness
Why is class(spectrum[["Ion"]]) after this "factor"?
spectrum <- cbind(spectrum,Ion=rep("",
nrow(spectrum)),Deviation.AMU=rep(0.0, nrow(spectrum)))
slowly going crazy ...
Joh
2009 Oct 28
5
PDF Corrupted?
I am running R 2.9.2 and creating a PDF that I am trying to open with Adobe Reader 9.2 but when I try to open it the reader responds with
"There was an error opening this document. The file is damaged and cannot be repaired.:
I am using the R command(s):
pdf(file="cat.pdf", title="Historical Sales By Category")
for(j in 1:length(master))
{
d <-
2011 Feb 08
1
Recuperate Spectrum() amplitude
Dear list,
I apologies first for my English, hope you will understand well my question.
I am working on 1/2 hour piezometric data, time unit is second. They
present daily oscillation when using the spectrum() function. What I am
really interested in, is to find the amplitude corresponding to this
oscillation.
I work with a college using Matlab, and although we apply the same
methodology, our
2011 Sep 23
1
Cross Spectrum : Conversion of 2-D spectrum into a single complex array
Hi, I'm wondering why the spectrum() phase of quadrature
couple isn't purely +/-pi.
But mostly, I'm looking for a recommended way to take a 2-D
spectrum and convert it into a single complex array.
Kindly consider:
# 10 Hz sine wave 10 seconds long sampled at 50 Hz
deltaT = 1/50
t = seq(0, 10, deltaT)
w = 2 * pi * 10
x = ts( sin( w * t ), deltat = deltaT )
y = ts( sin(
2011 Dec 16
1
simulation
I'm using an R program (which I did not write) to simulate multilevel data
(subjects in locations) used in power calculations. It uses lmer to fit a
mixed logistic model to the simulated data based on inputs of means,
variances, slopes and proportions:
?
(fitmodel <- lmer(modelformula,data,family=binomial(link=logit),nAGQ=1))
where modelformula is set up in another part of the program.?