Displaying 20 results from an estimated 300 matches similar to: "Savitzky-Golay smoothing -- an R implementation"
2009 Nov 18
0
Optimal parameters for Savitzky-Golay smoothing filter (loop)
Hi
I am running a Savitzky-Golay smoothing filter
(http://tolstoy.newcastle.edu.au/R/help/04/02/0385.html) for variables
in my dataset, dim (272:90). I managed to run the code for individual
variables in the dataset and then combine the results into a single
dataset. My novice attempt at this task is shown below
csg<-NULL
for (i in 1:ncol(data.all)) {
2003 Mar 21
1
Savitzky-Golay Derivative and Smoothing
If I'm not mistaken, that's sort of local polynomial with even degree and
fixed bandwidth (based on my own interpretation of description in Numerical
Recipes). You can do that with functions in the KernSmooth package.
HTH,
Andy
> -----Original Message-----
> From: wolf at micro-biolytics.com [mailto:wolf at micro-biolytics.com]
> Sent: Friday, March 21, 2003 1:43 PM
> To:
2011 Feb 22
2
Regarding Savitzky-Golay Smoothing Filter
Hi
When we use the sav_gol command in R , it shows an error which says: "
error in as.matrix". We've downloaded the necessary packages. Kindly
help us with this issue. If there is any other function to perform
Savitzky-Golay smoothing in R, please let me know.
With Regards
Reynolds
2004 Feb 05
2
Savitzky-Golay smoothing for reflectance data
I got a question from a fellow PhD student that work with spectrum
analysis in Excel and now he has lots of spectrums that needs to be
smoothed, which would be nice to be able to do in batch.
Is there an R package that can do:
Savitzky-Golay smoothing for reflectance spectral data
or a function that does something similar.
_______________________________________
Henrik Andersson
2004 Jan 27
1
asymptotic convergence of savitzky-golay?
Dear all,
Sorry if this is slightly off the track as far as R is concerned, but I
have been using the Savitzky-Golay filter to estimate some derivatives
of interest. I am wondering however, if anyone has seen anything in the
literature (or has any ideas) of how these estimates perform
asymptotically. Does anyone know what the rate of convergence is for these?
Thanks, matt.
2004 Oct 04
2
Weighted Savitzky-Golay?
Hi,
Does anyone know how to use weights and generate error bounds for
Savitzky-Golay? I have a (smallish) set of points y equally spaced each
with a known error and would like to smooth them using S-G but so as to
take into account the error already have and construct new error bounds
around them that take into account the errors they had at the beginning
and the erros they get as a result
2004 Jan 28
0
savitzky-golay derivatives?
Dear all,
Sorry if this is slightly off the track as far as R is concerned, but I
have been using the Savitzky-Golay filter to estimate some derivatives
of interest. I am wondering however, if anyone has seen anything in the
literature (or has any ideas) of how these estimates perform
asymptotically. Does anyone know what the rate of convergence is for
these as the sample size increases?
2002 Jun 27
1
Building from a source-code library under windows
Dear All,
I have a pair of .cpp and .def file can be compiled using VC++ and works
perfectly well in S-PLUS.
I wanted to do the same for R; so I followed the guidline given in "Building
from a source-code library under Windows" as much as possible and manage to
compile them using VC++ and call it from R. But it gives different answer
from the one called from S-Plus.
I know that I did
2008 Feb 23
1
ginv and matlab's pinv give different results
Dear all;
I'm kind of confused with the results obtained using the ginv function
from package MASS and pinv function from Matlab. Accroding to the
documentation both functions performs a Moore-Penrose generalized
inverse of a matrix X. The problem is when I change the tolerance
value, say to 1E-3.
Here is some output from ginv
195.2674402 235.6758714 335.0830253 8.977515484 -291.7798965
2005 Nov 03
0
problems with pan(): Indizierung ausserhalb der Grenzen = subscript out of bounds
Dear alltogether,
I tried pan() to impute NAs for longitudinal data.
The terminology in the following output follows the pan manpage. No data
are attached to this script as this may be too huge.
y = 15 responses
pred = at first just intercept was tried (later on covariates should follow)
subj = 168 different subjects with 4 to 6 observations for each subject
at time points t1, t2, ..., t6
#
2004 Jun 25
2
Matrix: Help with syntax and comparison with SparseM
Hi,
I am writing some basic smoothers in R for cleaning some spectral data.
I wanted to see if I could get close to matlab for speed, so I was
trying to compare SparseM
with Matrix to see which could do the choleski decomposition the
fastest.
Here is the function using SparseM
difsm <- function(y, lambda, d){
# Smoothing with a finite difference penalty
# y: signal to be smoothed
#
2008 Jan 28
1
Integer vs numeric
Hi the list.
I do not understand the philosophy behind numeric and integer.
- 1 is numeric (which I find surprising)
- 2 is numeric.
- 1:2 is integer.
Why is that ?
Christophe
2005 May 26
1
PAN: Need Help for Multiple Imputation Package
Hello all. I am trying to run PAN, multilevel
multiple imputation program, in R to impute missing
data in a longitudinal dataset. I could successfully
run the multiple imputation when I only imputed one
variable. However, when I tried to impute a
time-varying covariate as well as a response variable,
I received an error message, “Error: subscript out of
bounds.” Can anyone tell if my commands
2011 Nov 09
2
Problem with simple random slope in gam and bam (mgcv package)
Dear useRs,
This is the first time I post to this list and I would appreciate any
help available. I've used the excellent mgcv package for a while now
to investigate geographical patterns of language variation, and it has
has always worked without any problems for me. The problem below
occurs using R 2.14.0 (both 32 and 64 bit versions in Windows and the
64 bit version in Unix) and mgcv (both
2003 May 08
2
natural splines
Apologies if this is this too obscure for R-help.
In package splines, ns(x,,knots,intercept=TRUE) produces an n by K+2
matrix N, the values of K+2 basis functions for the natural splines with K
(internal) knots, evaluated at x. It does this by first generating an
n by K+4 matrix B of unconstrained splines, then postmultiplying B by
H, a K+4 by K+2 representation of the nullspace of C (2 by K+4),
2007 Sep 24
0
longitudinal imputation with PAN
Hello all,
I am working on a longitudinal study of children in the UK and trying the PAN package for imputation of missing data, since it fulfils the critical criteria of taking into account individual subject trend over time as well as population trend over time. In order to validate the procedure I have started by deleting some known values ?we have 6 annual measures of height on 300 children
2005 Aug 31
0
Imputation using Pan in R
Hi,
I've tried to run the multiple imputation for longitudinal data using Pan in
R.
The trimmed data consist 10 individuals across 4 time points.
Following the example in panex.R, I imputated the model with one y variable
and only random intercept.
It worked well.
The next step for me is to imputate a model with one y variable and both
random intercept and slope.
The program ran well, but
2011 Jun 21
0
R crash when using pan for multiple imputation
Dear R-List,
I apologize for not posting a reproducible example - the reason is that I
actually do not succeed in reproducing my specific problem with
generated data.
Let me still describe the problem:
I want to impute missing data using the "pan" package.
a) It works, when I use a fraction of my data (e.g. 200 out of 44000 cases)
b) It works, when I generate a dataset of equal
2008 Nov 25
1
how to check linearity in Cox regression
On examining non-linearity of Cox coefficients with penalized splines - I
have not been able to dig up a completely clear description of the test
performed in R or S-plus.
>From the Therneau and Grambsch book (2000 - page 126) I gather that the test
reported for "linear" has as its null hypothesis that the spline coefficient
is the same at the center of basis. Thus, in the example
2004 Oct 05
6
group change causing failure
OK, I searched through the archives and didn't find anything so I must be
doing something stupid.
I just compiled 2.6.3 and am trying to get it to run on linux 2.6.8.1 kernel
with a more or less fedora core2 environment. I was trying between two
systems but I have narrowed it down to what I believe is a pretty simple
case. Here is my setup/test:
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