Displaying 20 results from an estimated 2000 matches similar to: "IDWT - Inverse Discrete Wavelet Transform"
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
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
2009 Mar 22
1
using wavelet transform to calculate mean frequency of a signal
Dear list,
in short: I would like to calculate the mean frequency
of a signal (e.g. time series) using the wavelet transform.
with details: I did not find a R function to calculate a
mean frequency using one of the cran packages.
My searches using R Site Search returned:
**(1)waveclock {waveclock} R Documentation
Reconstruction of the modal frequencies in a time series using continuous
2005 Nov 29
1
wavelet transform
Hello,
I am thinking about plugging in Discrete Wavelet Transform as
described in Vorbis I spec:
1.1.2. Classification
Vorbis I is a forward-adaptive monolithic transform CODEC based on the
Modified Discrete Cosine Transform. The codec is structured to allow
addition of a hybrid wavelet filterbank in Vorbis II to offer better
transient response and reproduction using a transform better suited to
2010 Nov 25
2
Lifting Wavelet Transform
Hi R users
Thanks in advance
Is lifting wavelet transform implemented in R? If so, which package or codes can be used for performing that?
assaedi76@yahoo.com
Thanks
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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[0])<<1;
_RES[1]+=6*_X2[1]-_X2[2]-_X2[0];
2006 May 25
3
Wavelet Functions
Does R have any wavelet functions? When I type
> help.search("wavelet")
I get
" No help files found with alias or concept or title
matching 'wavelet' using fuzzy matching."
Thanks,
Peter.
2009 Jun 04
1
Morlet wavelet analysis
Dear,
I am using "cwt "function from Rwave package to perform Morlet wavelet analysis.
d1<-c(1.31673209591515, -0.171333455797346, -1.67618546079420,
-0.931604651010362, -0.954614183224057, -1.19821794547758, 0.516096363353144,
-0.0432811977638559, 0.737764943619919, 0.438046629673177, -0.208607167908743,
-0.3091308821262, -1.42473112931594, 0.234125312118165, -0.307047554490597,
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
2008 Sep 09
1
help on wavelet
Hi,
I have little experience using wavelet and I would like to know if it is
possible,using R wavelet package, to have a plot of frequency versus time.
thank you
giov
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Sent from the R help mailing list archive at Nabble.com.
2012 May 29
1
Help needed in wavelet transforming
Hello
I am currently working on forecasting hourly electricity prices where I am
required to do wavelet transformation. First I need to calculate
decomposition coefficients of the wavelet transform, then I need to select
wavelet function using multiresolution technique. I would be really
grateful if I can find any help in this matter.
Thanking You
with regards,
--
Name : Tarun Trivedi
Senior
2012 May 29
1
Help needed in wavelet transformation
Hello
I am currently working on forecasting hourly electricity prices where I am
required to do wavelet transformation. First I need to calculate
decomposition coefficients of the wavelet transform, then I need to select
wavelet function using multiresolution technique. I would be really
grateful if I can find any help in this matter.
Thanking You
with regards,
--
Name : Tarun Trivedi
Senior
2008 Dec 06
1
Morlet wavelet not supportd by wavCWTPeaks
aa <- (structure(list(X.0.85 = c(-1.02, -1.17, -1.29, -1.39, -1.46,
-1.5, -1.52, -1.5, -1.46, -1.39, -1.3, -1.19, -1.07, -0.93, -0.79,
-0.65, -0.5, -0.36, -0.22, -0.08, 0.05, 0.18, 0.3, 0.41, 0.52,
0.62, 0.72, 0.81, 0.89, 0.98, 1.05, 1.13, 1.19, 1.25, 1.29, 1.31,
1.31, 1.29, 1.24, 1.16, 1.06, 0.93, 0.77, 0.58, 0.38, 0.16, -0.07,
-0.31, -0.89, -1.05, -1.19, -1.31, -1.41, -1.47, -1.51, -1.51,
2007 Feb 01
1
Wavlet filter using morlet mother wavelet
Hi, List ,I am searching any package on R which can do wavelet filtering for mother wavelet morlet ,is anybody having any script for the same ? I am new to the RwAVELET ANALSSIS.. THANKS IN ADVANCE ANIL KUMAR ANIL KUMAR( METEOROLOGIST) LRF SECTION NATIONAL CLIMATE CENTER ADGM(RESEARCH) INDIA METEOROLOGICAL DEPARTMENT
2010 Aug 31
1
wavelet parameters with sowas
Hello everybody.
My name is Angela.
I'm doing wavelet using the sowas library. The problem I have is that I
don't know how to choose the paremeters to describes differnt wavelet
analysis. How I select the noctave, nvoice, w0, s0,...?
I hope my question is clear enough.
Thank you very much beforehand.
Angela
--
View this message in context:
2012 Mar 14
1
Wavelet Image Codec - advice
Hello,
Is is a great pleasure to post on a Xiph IRC Channel.I contacted you to
have your advice and comment about wavelets for image/video compression, as
I have made a wavelet-based image compression codec.
I know that currently the best image/video compression codecs use the DCT
block-based transform, like JPEG, Ogg Theora and the recent Google WebP,
for example, but what would you think of
2009 Jul 30
1
Re : Wavelet Kernel
Dear list,
I would like to fit a wavelet SVM model. Where can I find a wavelet
kernel function? Thanks in advance.
Stella Sim
DISCLAIMER:\ This email contains confidential informatio...{{dropped:11}}
2000 Dec 30
5
2d wavelet transforms
I've been reading up on wavelet transforms the past week,
and I plan to start on some video compression stuff next
week, if it's any good (small chance :)) for Tarkin.
So far I think I know what's happening, however there's one
small thing I don't quite understand yet. If I understand
correctly, you can do a 2d wavelet transform (I'm assuming
a Haar transform here for
2001 Jun 27
1
Wavelet audio codec by Adapted Wave Tech.
Following a post on vqf.com forum, I found out that some company called
Adapted Wave Technology is ready to release its audio codec based on
wavelets. They say that this wavelet-based codec is superior to MDCT codecs
by 30-50%.
One sentence caught my attention: "Adapted Wave Technologies holds exclusive
patent rights for applying wavelet packets to audio applications." - sounds
like a
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)