Displaying 20 results from an estimated 100 matches similar to: "mvfft"
1999 Apr 22
1
mvfft (PR#176)
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R-0.64.0 on RedHat Linux 5.1
Some problems with multivariate fast fourier transform. I
have attached the dump of a 30 x 3 matrix that seems to
reliably reproduce these problems
1) mvfft doesn't like vectors. It complains about not having
enough memory:
R>
2007 May 02
1
Is R's fast fourier transform function different from "fft2" in Matlab?
Hi All,
I found "mvfft" in R and "fft2" in Matlab give different result
and can't figure out why. My example is:
In R:
> matrix(c(1,4,2,20), nrow=2)
[,1] [,2]
[1,] 1 2
[2,] 4 20
> mvfft(matrix(c(1,4,2,20), nrow=2))
[,1] [,2]
[1,] 5+0i 22+0i
[2,] -3+0i -18+0i
In Matlab:
>fft2([1,2;4,20])
ans=
27 -17
-21 15
Does any function in R
2001 Jun 04
1
2D convolution
Dear all,
I have an image that I need to filter, and so I'm looking for a method to
convolve it with a matrix. If I understood the docs for convolve
correctly, it only works in 1D (and I have tried to convolve, it didn't
look good).
So, I wondered if anybody have implemented 2D convolution in R, or have
any good advices to share (beyond having a look at mvfft), before I go
hacking?
2003 May 20
1
R-1.7.0 'make check' fails on reg-tests-1
Dear all,
I am trying to upgrade R-1.6.2 to R-1.7.0 on an SGI running IRIX6.5.
Everything compiles but I get an error in the testing phase:
[snip]
running regression tests
make[3]: Entering directory `/usr/local/src/R-1.7.0/tests'
running code in 'reg-tests-1.R' ...make[3]: *** [reg-tests-1.Rout] Error 1
make[3]: Leaving directory `/usr/local/src/R-1.7.0/tests'
make[2]: ***
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
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
2010 Apr 29
3
dump not evaluating promises?
I'm using the dump command to pass data to WinBUGS/OpenBUGS/JAGS and have run
into a problem.
Here is some R-code:
foo <- array(1:6, dim=c(2,3))
dump('foo', file='dumpdata.R')
dump('foo', file='dumpdata.R', append=TRUE, evaluate=TRUE)
foo2 <- array(c(2,3,5,7,9,7,5,3), dim=c(2,4))
dump('foo2', file='dumpdata.R', append=TRUE)
And here is
1997 Apr 23
1
R-beta: Version 0.49 Released
The newest version of R for Unix (version 0.49) is now available
(or soon will be) from the following sites.
NORTH AMERICA:
http://lib.stat.cmu.edu/R/Alpha
EUROPE:
ftp://ftp.stat.math.ethz.ch/R/
ftp://statlab.uni-heidelberg.de/pub/mirrors/auckland/R/
JAPAN:
ftp://ftp.u-aizu.ac.jp/pub/lang/R/
NEW ZEALAND:
ftp://stat.auckland.ac.nz/pub/R/
Please
1997 Apr 23
1
R-beta: Version 0.49 Released
The newest version of R for Unix (version 0.49) is now available
(or soon will be) from the following sites.
NORTH AMERICA:
http://lib.stat.cmu.edu/R/Alpha
EUROPE:
ftp://ftp.stat.math.ethz.ch/R/
ftp://statlab.uni-heidelberg.de/pub/mirrors/auckland/R/
JAPAN:
ftp://ftp.u-aizu.ac.jp/pub/lang/R/
NEW ZEALAND:
ftp://stat.auckland.ac.nz/pub/R/
Please
1997 Apr 23
1
R-beta: Version 0.49 Released
The newest version of R for Unix (version 0.49) is now available
(or soon will be) from the following sites.
NORTH AMERICA:
http://lib.stat.cmu.edu/R/Alpha
EUROPE:
ftp://ftp.stat.math.ethz.ch/R/
ftp://statlab.uni-heidelberg.de/pub/mirrors/auckland/R/
JAPAN:
ftp://ftp.u-aizu.ac.jp/pub/lang/R/
NEW ZEALAND:
ftp://stat.auckland.ac.nz/pub/R/
Please
2006 Feb 02
0
How do I normalize a PSD?
Dear Tom,
Short answer, if your using spec.pgram(), use the smoothing kernel to get a
better estimate at the frequency centered in the bandwidth. If your
frequency bin of interest is wider than the bandwidth of the kernel, average
across frequencies (I think). The estimate appears to be normalized already.
If you are calculating your PSD independently, then oversample (e.g. 2,
perhaps 4 or more
1999 Mar 31
2
"dump" Splus -> R
Hi All,
I just used "dump" on Splus to transfer a pile of survival objects from
Splus 3.4 on Solaris 7 to R 0.63.3 on Intel.
The only trick is that survival objects contain an element holding the
original call that generated the object. When Splus writes these out, it
doesn't mark them in any way, so when R tries to read them in, it ends up
trying to reevaluate the call. Not
1999 Mar 31
2
"dump" Splus -> R
Hi All,
I just used "dump" on Splus to transfer a pile of survival objects from
Splus 3.4 on Solaris 7 to R 0.63.3 on Intel.
The only trick is that survival objects contain an element holding the
original call that generated the object. When Splus writes these out, it
doesn't mark them in any way, so when R tries to read them in, it ends up
trying to reevaluate the call. Not
2002 Feb 21
0
plot.hclust: strange behaviour with "manufactured"
This worked for me with your example:
source("dumpdata.R")
storage.mode(x.hc$merge) <- "integer"
plot(x.hc)
(R-1.4.1 compiled from source on WinNT4.)
Andy
> -----Original Message-----
> From: Hugh Chipman [mailto:hachipma at icarus.math.uwaterloo.ca]
> Sent: Wednesday, February 20, 2002 5:32 PM
> To: andy_liaw at merck.com
> Cc: r-help at stat.math.ethz.ch
2003 Aug 06
1
contour lines intersect
Hi,
Sorry if this is already known...
contour() sometimes draws contour lines that intersect.
Is there a temporary fix?
A dataset which causes problems is at
http://www.maths.uwa.edu.au/~adrian/dumpdata.R
If you try just
source("dumpdata.R")
image(huh)
contour(huh)
the 100 x 100 matrix 'huh' contains an hourglass-shaped region
of values around 0.8. The contour plot
2002 Feb 20
1
plot.hclust: strange behaviour with "manufactured" hclust object
I've been trying to get plot.hclust to work with a hclust object I
created and have not had much success. It seems that there is some
"hidden" characteristic of a hclust object that I can't see. This is
most easily seen in the following example, where plot.hclust works on
one object, but when this object is "dumped" and then re-read,
plot.hclust no longer works. Is
2012 Feb 20
4
r: (1, 'Internal error', 'panic: xc_dom_core.c:273: xc_dom_do_gunzip: inflate failed (rc=-3)').. only on Intel hardware and only under 32-bit dom0
The combination is bit awkward so not sure why this is happening, but with
Xen 4.1.x hypervisor (64-bit), with a 32-bit dom0 (3.3-rcX or 3.2) and with a 3.3-rcX or 3.2 domU
I get this:
sh-4.1# Feb 20 17:47:41 tst006 init: reloading /etc/inittab
xl info
host : tst006.dumpdata.com
release : 3.3.0-rc4
version : #1 SMP PREEMPT Mi686
nr_cpus
2001 Jun 29
1
KS test in R.1.3.0 has incorrect p-values. (PR#1004)
Based on a report to the Windows maintainers from Richard Rowe
<Richard.Rowe@jcu.edu.au>:
NEWS for 1.3.0 says
o Exact p-values are available for the two-sided two-sample
Kolmogorov-Smirnov test.
I think the (new) p-values are computed but are backwards:
> set.seed(123)
> x <- rnorm(50)
> y <- runif(50)
> ks.test(x,y, exact=T)$p
[1] 1
> 1 - ks.test(x,y,
2007 May 28
1
where did the factor name go
> tmp <- data.frame(y=rnorm(12), a=factor(rep(letters[1:4],3)))
> tmp
y a
1 -0.60866099 a
2 0.55500538 b
3 0.12231693 c
4 -0.24613790 d
5 -0.09253593 a
6 -1.54652581 b
7 0.17204210 c
8 -1.22778942 d
9 1.22151194 a
10 -0.43982577 b
11 -1.25444287 c
12 -0.97251060 d
> tmp.aov <- aov(y ~ a, data=tmp)
> summary(tmp.aov)
Df Sum Sq Mean Sq F value
2007 Oct 30
2
R can't source() long lines (PR#10383)
Full_Name: Martin Kober
Version: 2.6.0
OS: Vista & Linux
Submission from: (NULL) (137.208.185.169)
Hi!
I just stumbled upon a problem with file source()ing:
R will fail to source a file if it contains lines longer than about 8192 bytes
("input buffer overflow").
While it's save to say that human-written code won't contain lines that long,
dump()ed data structures may