Displaying 20 results from an estimated 38 matches for "dwt".
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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
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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...
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)
data<-c(936.944,936.944,936.944,936.944,936.944,936.944,936.944,936.944,936.944,936.944,936.944,936.944,936.944,916.994666666667,909.592,941.8,961.933333333333,987.8,969.2,934.866666666667,912.8,913.266666666667,928.2,949....
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...
2009 Feb 24
0
Wavelet Bootstrap Size Simulation
...- fitphi(data,x,i)
}
for (j in 1:length(x)){
Rn[j]<-(24/j)*length(data)*sum((coeff[1:j])^2)
}
max(Rn)
}
#The function used to find the wavelet bootstrap replicate of the original
series
wavestrap <- function (y, wf = "d8", J = log(length(y), 2) - 1, infl =
sqrt(1.1)){
y.dwt <- dwt(y, wf, n.levels = J)
resample.dwt <- y.dwt
for (i in 1:(length(y.dwt)-1)) {
resample.dwt[[i]] <- sample(y.dwt[[i]]*infl, replace = TRUE)
}
idwt(resample.dwt)
}
#The simulation:
arcoeff<-.9 #AR(1) Coefficient
T<-128 #Realization Length
bsreps<-30...
2009 Jan 07
0
How-To extract data from a matrix of lists subject to a set of given constraints
My goal is to store the DWT coefficients from a number of time series in such a way to be able to extract subsets satisfying giben conditions.
I have defined the following 11 matrices whose x-axis represent time intervals and y-axis represent the number of time series:
MS <- 11 d1.mat <- matrix (data=list(),...
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 cod...
2001 Nov 09
1
Installing packages
...-fPIC -O3 -fomit-frame-pointer -pipe -mcpu=pentiumpro -march=i586
-ffast-math -fno-fast-math -c bell-p-w.f -o bell-p-w.o
gcc -I/usr/lib/R/include -I/usr/local/include -mieee-fp -D__NO_MATH_INLINES
-fPIC -O3 -fomit-frame-pointer -pipe -mcpu=pentiumpro -march=i586
-ffast-math -fno-fast-math -c dwt.c -o dwt.o
gcc -I/usr/lib/R/include -I/usr/local/include -mieee-fp -D__NO_MATH_INLINES
-fPIC -O3 -fomit-frame-pointer -pipe -mcpu=pentiumpro -march=i586
-ffast-math -fno-fast-math -c hosking.c -o hosking.o
gcc -shared -o waveslim.so bell-p-w.o dwt.o hosking.o -L/usr/local/lib
-lg2c -lm -L/u...
2005 Nov 23
1
help on list
Hi,
New to R,
having done a wavelet analysis i got a result as list.
The problem I have is : how can I acces to a given element of the list.
here is what I get from my variable scale_d28
>typeof(scale_d28)
[1] "list"
> length(scale_d28)
[1] 1
and scale_d28 is a list of 100000 double values?
Thanks
--
Jean Pierre BOTH
phone (33) 01.69.08.84.78 (work)
email
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"...
2009 Feb 20
0
package "wavelets" does nor recognize filter "d2"
I take the liberty of pasting the on-line documentation for package "wavelets", functions "dwt" and "wt.filter", pertinent to the wavelet/filter choice.
While I apologize for my verbose messages with huge attachments, I encourage whoever loads packages to CRAN to take some minutes to reread the attached documentation.
Usage
dwt(X, filter="la8", n.levels, boundary...
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...
1999 Nov 19
2
Impulses
...o make sure that no one has gone
down this path before:
Roughtly vorbis currently does:
input wave -> MDCT -> LPC -> LSP -> quant -> ------------------>output
\->delpc->error->quant -^
What do you think of this:
input wav -> DWT -> sum non-impuse factors -> iDWT -> MDCT ... (like above)
\
-> -> sum impulse factors -> iDWT -> LPC -> LSP -> quant
i.e. use a wavelet transform to seperate out impulsey signals and
compress them in the time domain.
The decoder complexity...
2007 Nov 24
1
Indexing and partially replacing 99, 999 in data frames
...dataset also includes 99
entries as true values. So, here is what I did:
#to remove all 999:
babies[babies==999] <- NA
, but to remove the 99 in columns nr. 10,12,17 I have come to a complete
stop. The corny idea of
babies$ht[babies$ht==99] <- NA
babies$dht[babies$dht==99] <- NA
babies$dwt[babies$dwt==99] <- NA
works, but seems to show that I have not really understood the art of
indexing, have I? The archives did not really offer enough insight for
me to solve the problem, I am ashamed.
I tried something with
babies[is.element(babies[,c(10,12,17)], 99)] <- NA # beeep, wrong...
2017 Sep 04
0
NHW Project - fast discrete wavelet transform
Hello,
I forgot in my last reply that my DWT implementation can be speed up, for
example I'm doing for now:
for (;_X1<_E_;_X1++,_RES+=2) //dilatation
{
_RES[0]=_X1[0]<<3;
_RES[1]=(_X1[1]+_X1[0])<<2;
}
then
for (;_X2<_E_;_X2++,_RES+=2) //details
{
_RES[0]-=(_X2[1]+_X2...
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
Se...
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 kalman filter does a good job on my data but tends to dampen spikes too
much so i was looking to compare its perfo...
2009 Mar 04
1
flaw in CRAN package "wavelets": Daubechies "d8" not recognized by function wt.filter
> wt.filter("d8") #### HOW COME ????
Error in validObject(.Object) :
invalid class "wt.filter" object: invalid object for slot "transform" in class "wt.filter": got class "function", should be or extend class "character"
> wt.filter("d10") # OK
An object of
2010 Sep 03
2
Package wavelets
Hi user's
Does anybody work with wavelets on R?
Please I need some help.....!!!!
Atte
Marize Sim?es
--
View this message in context: http://r.789695.n4.nabble.com/Package-wavelets-tp2526023p2526023.html
Sent from the R help mailing list archive at Nabble.com.
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.
--
Dinesh Vakamudi
S...