Displaying 20 results from an estimated 400 matches similar to: "understanding DWT"
2012 Mar 17
3
how to call functions with same name but in different package?
hi everyone .
I am trying to use some packages but there are some functions have the same
name in different package.
for example
dwt function
both in packages wavelets and waveslim
dwt(X, filter="la8", n.levels, boundary="periodic")
How can I avoid mixing them up ?
--
TANG Jie
Email: totangjie@gmail.com
Tel: 0086-2154896104
Shanghai Typhoon Institute,China
2005 Nov 04
1
problem in waveslim library?
This code consistenly segfaults for me. Can someone please take a look
and tell me if the problem is due to something I am doing or is there a
problems with the dwt (idwt) functions in the waveslim library.
Thanks
tom
library(waveslim)
2001 Nov 09
1
Installing packages
Hello,
I have upgraded from Mandrake Linux 8.0 to Mandrake 8.1 and try to reinstall
my favourite R... Everything is OK for the base software but I have trouble
to get some packages installed.
Specifically, for some packages, a "collect2" binary seems to be necessary
during the compilation/linking process of the library, and LD complains about
not finding it :
Installing source
2002 Oct 27
1
denoising univariate data with wavelets
Hi,
I am interested in a applying wavelets as a smoothing tool for my
(1-dimensional) data. I looked into wavetresh and waveslim packages but
could not quite figure out an obvious way to do this after running dwt or
wt functions. Would someone be able to point me in the right direction on
how to denoise univariate data using one of wavelet packages available in
R?
Thank you very much
Jane
ps
2006 Jan 08
2
Filters in waveslim
Dear R Users,
For running wavelet functions using dwt( ), modwt( ), and mra( ), a wavelet filter algorithm is applied. For all these functions, default is "la8" and other possibility is "haar". In related documents, another possibilities like as symlet and coiflet ... are not cited.
Besides "la8" and "haar", which wavelet filters can be used?
Thank
2008 Dec 28
0
how to calculate DWT maximum decomposition level
Given a time series of length N, I am trying to figure out its maximum DWT decomposition level.
With reference to "dwt" function of R package "wavelets", running the provided example I get the following
and wonder how the maximum decomposition level (which is not an integer number) is calculated.
I tried myself the formula in the on-line documentation but could not get the
2009 Feb 24
0
Wavelet Bootstrap Size Simulation
I have written a short script to estimate the size of a test of non-constant
mean in an AR(1) time series. When I run the simulation on my PC (R version
2.7.1), I get the expected result: an empirical size much larger than the
nominal size. On the Red Hat machine (R version 2.7.2) in my department,
however, I get p-values > .45 for every simulated test. Below is my
simulation code (uses
2009 Oct 16
2
what's the R code for wavelet decomposition (Haar transformation)?
Dear all,
Using R function "dwt", it seems that I cannot specify the wavelet
transformation like Haar. What's the R code for wavelet decomposition
which allows me to specify Haar wavelet transformation? Of course, if it
can include "db2", that is even better. In general, I want an R function
like matlab code "dwt". Thanks in advance!
Zhen Li
2006 Nov 14
1
??: Re: Need help in waveslim package: imodwt and universal.thresh.modwt
Airon,
I used R2.4.0 on a Windows XP (SP2) (not Chinese :-))
and it still works:
> data = read.csv("u:/airon.csv")
> xdata = data$Adj..Close
> modwt.la8 = modwt(xdata, "la8", n.level=6)
> summary(modwt.la8)
Length Class Mode
d1 1467 -none- numeric
d2 1467 -none- numeric
d3 1467 -none- numeric
d4 1467 -none- numeric
d5 1467 -none- numeric
d6 1467
2001 Nov 05
1
name resolution across subnet bounderies
I do get problems with name resolution accross subnet bounderies.
I have a working and wins server and to demonstrate the problem I
paste the debug output of
mount /smbhome/
opts: uid=1000
opts: gid=1000
mount.smbfs started (version 2.2.2debian-2)
added interface ip=192.168.6.2 bcast=192.168.6.255 nmask=255.255.255.0
resolve_lmhosts: Attempting lmhosts lookup for name Tri-st-s001<0x20>
2010 Dec 22
1
tests on polr object
Using ordered probit model, I get errors from dwt and bptest.
dwt:
Error in durbinWatsonTest.default(...) : requires vector of residuals
bptest:
Error in storage.mode(y) <- "double" :
invalid to change the storage mode of a factor
I imagine I have to restate as an individual probit model for each category,
but is there an easier way?
thanks,
bp
[[alternative HTML version
1999 Nov 19
2
Impulses
After playing with the vorbis code for a while and doing tons of hacks and
analysis on it, I've found it to perform very poorly with impulse signals.
The MDCT seems to cause lots of spreading, and it seems to result in much
worse impulse performance then mp3.
What is the current plan on handling this? Will a smart quantizer be able
to avoid it?
I've been looking at various ways of
2007 Nov 24
1
Indexing and partially replacing 99, 999 in data frames
Dear WizaRds,
unfortunately, I have been unable to replace the '99' and '999' entries in
library(UsingR)
attach(babies)
as definitions for missing values NA, because sometimes the 99 entry is
indeed a correct value. Usually, or so I thought, NAs can
easily replace a, say, 999 entry via
mymat[mymat==999] <- "yodl"
in a matrix or data frame. Alas, the babies'
2003 Feb 02
1
unable to open connection
Dear list members,
I have problem to load data of the library waveslim.
After I load the library waveslim and tried to load data ibm
data(ibm)
Error in file(file, "r") : unable to open connection
In addition: Warning message:
cannot open file `ibm.txt''
I also tried other data sets without success. It works for other
libraries though.
Any suggestions? Thanks.
Zhu Wang
2006 Nov 15
2
??: Re:??: Re: Need help in waveslim package: imodwt and universal.thresh.modwt
Airon,
I don't think you have to find an English computer 'cause the
following must work in your Chinese one :-)
Let me explain. First of all, change your lines to
xdata <- ckhdat$Adj..Close[1:1447]
#names(ckhdwt.la8) <- c("w1", "w2", "w3", "w4", "w5","w6", "v6")
note the # sign, i.e., DO NOT change the names
2010 Aug 04
1
wavlet transform
Hello
I do wavelet transform by using this code:
dec=dwt(ld, filter='d8', n.levels=lev, boundary="reflaction");
dec consists of the decomposition coefficients and other
How can I change the coefficients the decomposition manualy?
--
View this message in context: http://r.789695.n4.nabble.com/wavlet-transform-tp2313427p2313427.html
Sent from the R help mailing list archive at
2003 Aug 20
1
aide
Bonjour,
J'aimerais savoir si quelqu'un pourrait m'aider en ce qui concerne l'utilisation
du package waveslim.
Je voudrais savoir comment on fait pour revenir a un signal d'origine lorsque
l'on dispose de coefficients de detail et d'approximation.
Merci d'avance
Tuleau Christine
(christine.tuleau at math.u-psud.fr)
2004 Jan 21
1
Mac OS X and R
My Windows machine has gone "kaput" and I am trying to see how R might
work on my Mac. I am interested in using the contributed packages,
especially "waveslim" and "wavethresh". Are all packages available
under either Windows, Mac, or Unix? I can't seem to tell from the
documentation whether this is so (probably because I am not very
computer literate!). Any
2002 Nov 06
2
Re: some questions!
Hi,
I'm also cc'ing it to r-help.
On Wed, 6 Nov 2002, Kenneth Cabrera wrote:
> Date: Wed, 06 Nov 2002 10:09:21 -0500
> From: Kenneth Cabrera <krcabrer at perseus.unalmed.edu.co>
> To: kwan022 at stat.auckland.ac.nz
> Subject: some questions!
>
> Hello Dear Ko-Kang Wang:
>
> I am trying to compile R v 1.6.1 .
>
> I am following the
2012 May 30
1
Help needed for this error
> results <- mra(x$w1mcp, filter = "d4", n.levels = 3, boundary =
"periodic", method = "dwt")
> write.csv(results, "c:/mydata.csv")
Error in as.data.frame.default(x[[i]], optional = TRUE) :
cannot coerce class 'structure("mra", package = "wavelets")' into a
data.frame
I am not able to access data stored in results.