similar to: Integer vs numeric

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

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

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

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.

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:

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.

Hello Masters, I run the loess() function to obtain local weighted regressions, given lowess() can't handle NAs, but I don't improve significantly my situation......, actually loess() performance leave me much puzzled.... I attach my easy experiment below #------SCRIPT---------------------------------------------- #I explore the functionalities of lowess() & loess() #because I have

Hi, all, I want to use lowess(x, y) where x and y are vectors of length of 4000+. In fact, x and y are log of some vectors. So, some of the elements are NaN. lowess() can not take away those elements then do the fitting. It will give the error message and do nothing. 1. Can anybody tell me how to get rid of those NaN's and use lowess()? 2. How to get the LOWESS fitting values for any

Hi, I have a scatter plot of the variables GNI and Lifeexp (Gross National Income and Life Expectancy, both metric). So I plotted them and I want to add a regression line and a lowess line. I use lowess and not loess because I have missing values. My code: plot(GNI,Lifeexp) abline(lm(Lifeexp~GNI), col="red") y.loess<-loess(Lifeexp~GNI,na. action = na.exclude)

Colleagues ---------------------------------- System info: R version rw1022 on NT ESS v. 5.1.18 using emacs ver. 20.4 ---------------------------------- I would like to access the residuals from a lowess fit (function lowess() ) as an aid to assessing whether I am over-smoothing or under-smoothing a dataset (as in Cleveland's book "Visualizing data", section 3.3) Unless I

Dear all, To draw a lowess line on a plot was a piece of cake; to draw a loess line, however, seems not that easy. Is the loess plotting implemented at all in relation to the loess function, or do I have to look in add-on packages? Thanks, Marcin

Dear R-community, maybe someone can help me with this: I've been using the loess() smoother for quite a while now, and for the matter of documentation I'd like to resolve the acronym LOESS. Unfortunately there's no explanation in the help file, and I didn't get anything convincing from google either. I know that the predecessor LOWESS stands for "Locally Weighted

As I've mentioned a number of times. I find it very useful to have lowess() become a generic function so that a lowess.formula() can be defined. Below is a patch that makes both changes, as well as updating the corresponding help documentation. Gregory R. Warnes Manager, Non-Clinical Statistics Pfizer Global Research and Development Tel: 860-715-3536 ? DESCRIPTION ? Makefile ?

Hi Every Body, I don't know why some regression functions have no related prediction function. For example lowess, loess, lokerns, lpridge, lpepa, and ksmooth. What could help? Is there any global or wrapper function so that can help? Regards, Amir Safari --------------------------------- [[alternative HTML version deleted]]

Hi there, I'm plotting some glass RI values just by plotting plot(x) then I put on my lowess smoother lines(lowess(x)) now I want to put on some 95% Confidence Interval bands of the lowess smoother, but don't know how?? Thanks -- Gareth Campbell PhD Candidate The University of Auckland P +649 815 3670 M +6421 256 3511 E gareth.campbell@esr.cri.nz gcam032@gmail.com [[alternative

code: x <- rnorm(32) y <- rnorm(32) plot(x,y) lines(lowess(x,y),col='red') Now I need to sample the lowess function into matrix where one series will be X and other will be values of lowess at particular X. -- View this message in context: http://r.789695.n4.nabble.com/how-to-sample-lowess-loess-into-matrix-tp3053458p3053458.html Sent from the R help mailing list archive at

Hi there, I cant seem to find a way for the lowess smoothing function to handle "NA" values. Can anyone help?? Regards, Wayne Dr Wayne R. Jones Statistician / Research Analyst KSS Group plc St James''s Buildings 79 Oxford Street Manchester M1 6SS Tel: +44(0)161 609 4084 Mob: +44(0)7810 523 713 KSS Ltd A division of Knowledge Support Systems Group plc Seventh Floor St

Dear all, please do you have any recommendation about a more advanced function in R for lowess/loess regression ? the basics lowess() or loess() do not perform as well as I would expect. thanks very much, Bogdan [[alternative HTML version deleted]]

I'm using this code to plot a smoothed line. These two columns of data really represent 4 groups and I'd like to plot a separate line for each group but have them all in the same plot. The R-Docs for lowess do not seem to indicate some type of "GROUPS=var_name" option. What would be the syntax for this? plot(AWGT ~ lipid ) lines(lowess(lipid , AWGT, f=.8)) -- Dean

I was trying to plot some data in R. I used the following code to draw a loess fit and got the output as >?lines(lowess(log(abs(t(res))), log(abs(t(synthesised)))), col="red") Error in lowess(log(abs(t(res))), log(abs(t(synthesised)))) :?? NA/NaN/Inf in foreign function call (arg 1) Then I thought to use your Limma package for background correction. Do you think it's a right