Displaying 20 results from an estimated 500 matches similar to: "problem in waveslim library?"
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
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
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
2006 May 25
1
understanding DWT
Can someone please help me understand the examples given in the dwt
function of the waveslim library
library(waveslim)
?dwt
I'm having a problem understanding these lines. I assume they are
required because of how the algorythm deals with the signal bounderies.
Am I correct in thinking that for wavelets of scale 1 and 2, the
coefiecints need to be shifted by 2 places, for scale 3 and 4 shift
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
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
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
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 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$Adj..Close
> modwt.la8 = modwt(xdata, "la8", n.level=6)
> summary(modwt.la8)
Length Class Mode
d1 1467 -none- numeric
d2 1467 -none- numeric
d3 1467 -none- numeric
d4 1467 -none- numeric
d5 1467 -none- numeric
d6 1467
2006 Nov 12
2
Need help in waveslim package: imodwt and universal.thresh.modwt
Hi:
I have encountered problems with imodwt and universal.thresh.modwt and cannot find any reference in R Search. Hope someone can give me some ideas:
Starting with
modwt.la8 <- modwt(xdata, "la8", n.level=6) <-- this seems to work fine
(1) ydata <- imodwt(modwt.la8)
will always give ydata as numeric(0) (no values) instead of being a time series data with
2009 Oct 16
2
what's the R code for wavelet decomposition (Haar transformation)?
Dear all,
Using R function "dwt", it seems that I cannot specify the wavelet
transformation like Haar. What's the R code for wavelet decomposition
which allows me to specify Haar wavelet transformation? Of course, if it
can include "db2", that is even better. In general, I want an R function
like matlab code "dwt". Thanks in advance!
Zhen Li
2006 Nov 15
2
??: Re:??: Re: Need help in waveslim package: imodwt and universal.thresh.modwt
Airon,
I don't think you have to find an English computer 'cause the
following must work in your Chinese one :-)
Let me explain. First of all, change your lines to
xdata <- ckhdat$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 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
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'
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.
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
2012 Jan 16
0
Package: Waveslim Error: The object is this type is not subsettable
Hi everyone
I am using the wavelet and waveslim package in R to find the wave
variance.Here is the code
return.modwt<-modwt(X, filter="la8", n.levels=5, boundary="periodic",
fast=TRUE)
return.modwt.var<- wave.variance(return.modwt, type="nongaussian")
Where X is a uni-variate time series.
I am expecting a matrix with 5 rows(no. of levels) and 3
2004 Nov 01
0
updated package waveslim 1.4
waveslim 1.4 has recently been uploaded to CRAN and is fully compatible
with Rv2.0. Besides ensuring usability with the most recent version of R,
two additional "flavors" of wavelet methodology have been added to the
package: (1) Hilbert wavelet pairs and (2) the dual-tree complex wavelet
transform [only 1D and 2D ported from Matlab code by Selesnick]. The
dual-tree CWT code has
2004 Nov 01
0
updated package waveslim 1.4
waveslim 1.4 has recently been uploaded to CRAN and is fully compatible
with Rv2.0. Besides ensuring usability with the most recent version of R,
two additional "flavors" of wavelet methodology have been added to the
package: (1) Hilbert wavelet pairs and (2) the dual-tree complex wavelet
transform [only 1D and 2D ported from Matlab code by Selesnick]. The
dual-tree CWT code has
2006 Nov 16
0
??: Re:??: Re:??: Re: Need help in waveslim package: imodwt and universal.thresh.modwt
Airon,
I'm not sure I have understood your question. Anyway, it
seems to me that you'll have to code a little. Take a look
at ?modwt. I think you'll have to put zeros each scale a time
except the one you want to reconstruct. Then do imodwt.
After some small loop, I think you'll get the desired result.
HTH,
Rogerio.
---------- Cabe?alho original -----------
De: "Airon