Displaying 20 results from an estimated 500 matches similar to: "Savitzky-Golay smoothing for reflectance data"
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
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:
2004 Feb 06
1
Savitzky-Golay smoothing -- an R implementation
As the request for the Savitzky-Golay Algorithm in R has come up several
times, I here include my implementation based on code written for Matlab.
Savitzky-Golay uses the pseudo-inverse pinv() of a matrix. There is an
'generalized inverse' ginv() in the MASS package, but I use a simpler form
because I didn't want to 'require' MASS any time I apply Savitzky-Golay.
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 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.
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)) {
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?
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
2008 Sep 26
2
axis in a normal plot
Hi
I have a small problem, I'm new in using R, so I hope you can help me...
I'm running a logistic regression model and want to do a nice plot.
The plot I have made is done a plot with the command jitter:
plot(jitter(overto$age[overto$sex=="F"]),jitter(overto$neg.pos[overto$sex=="F"]),xlab="age",ylab="neg and pos")
my responsvariable is positive
2007 May 04
1
rgl install on rhel4 x86_64
I'm trying to install rgl 0.71 on a redhat enterprise 4, x86_64. I have
tried using R 2.2.1, 2.3.1, and 2.5.0. I have successfully installed
this version of rgl, using R 2.2.1 on an rhel4 i386 host. On the x86_64
host, I receive the following configuration error:
checking GL/gl.h usability... no
checking GL/gl.h presence... yes
configure: WARNING: GL/gl.h: present but cannot be
2004 Feb 06
0
multiple plots in different windows
At 14:29 05-02-2004, you wrote:
>Hi all,
>I'd like to generate a number of plots to compare different
>vectors I have stored in a list. To do this I do something like
>(in a linux system):
>
>for(i in 1:L) {
> X11()
> plot(listOfFunctions[[i]])
>}
>
>First question is: is this the right way to create several plots (in
>different windows) ?
Hi
I think
2009 Oct 27
4
automatically adjusting axis limits
Dear R users,
I am a newbie. Just switched from MATLAB. So thanks a lot for your
patience.
I have 50000 spectra collected in field. Each spectra has two columns :
Wavelength (56) and the actual measurement.
Each measurement came in a different .txt file on disk (50000 files in
total). I wrote a script that reads every spectra in a for loop and
constructs two variables :
Wavelength (56) and
2010 May 11
1
Gasoline Data in pls package
Hi -
I am using pls package for some pcr computations. There is a data set called
gasoline.
Would someone be able to tell me what command(s) could be used to produce
this graph in R? I am not sure where the log(1/R) - Y-axis - are coming
from
Thanks much
Ravi
2007 Nov 28
0
Power Spectral Sensity
I am working with a dissolved oxygen dataset. continuous readings are taken
at 15 minute intervals and we have been recording these data at 12 stations
along the savannah river for two years now. The longest set of readings
that are continuous without interuption is 53 days. I would like to look at
the power spectral density at each of these sites (most likely one day will
be the overridding
2008 May 05
0
quantitative spectra analysis
look at the spectrums before you do the cbind - I would not suggest letting
R wrap the data to fill in a data frame. I would suggest using something
that you "know how it acts" in the frequency domain like zero. You are
probably introducing periodicies that are not real, and I would suggest not
to go down this path. As for finding commonalities amongst signals- it all
depends on what
2017 Jul 13
3
How to formulate quadratic function with interaction terms for the PLS fitting model?
I have two ideas about it.
1-
i) Entering variables in quadratic form is done with the command I
(variable ^ 2) -
plsr (octane ~ NIR + I (nir ^ 2), ncomp = 10, data = gasTrain, validation =
"LOO"
You could also use a new variable NIR_sq <- (NIR) ^ 2
ii) To insert a square variable, use syntax I (x ^ 2) - it is very
important to insert I before the parentheses.
iii) If you want to
2017 Jul 13
2
Quadratic function with interaction terms for the PLS fitting model?
Dear all,
I am using the pls package of R to perform partial least square on a set of
multivariate data. Instead of fitting a linear model, I want to fit my
data with a quadratic function with interaction terms. But I am not sure
how. I will use an example to illustrate my problem:
Following the example in the PLS manual:
## Read data
data(gasoline)
gasTrain <- gasoline[1:50,]
## Perform
2005 Jan 13
3
as.character methods
Hello,
?as.character says that the as.character function is a generic with
usage: as.character(x, ...). So, I want to create an S4 object with an
as.character method following the above usage, but I get the below error
telling me that ... isn't in the generic for as.character.
> setClass("tmp", "numeric")
> setMethod("as.character", "tmp",
2005 Jan 13
3
as.character methods
Hello,
?as.character says that the as.character function is a generic with
usage: as.character(x, ...). So, I want to create an S4 object with an
as.character method following the above usage, but I get the below error
telling me that ... isn't in the generic for as.character.
> setClass("tmp", "numeric")
> setMethod("as.character", "tmp",
2010 Apr 26
1
Just about "approximate F-test"
Hi, Dear R community,
These is a paper of "Wheat Grain Yield Response to N Application
Evaluated through Canopy Reflectance".
This paper of "Materials and Methods" said "A single regression equation
relating A and B was derived for each location using PROC NLIN (SAS
Inst. 1990). Slopes and intercepts for the independent regressions were
compared with an *approximate