search for: marquardt

Hi All, Is the Levenberg-Marquardt algorithm available in R. This method combines the steepest descent algorithm and Newton's method. Thanks in Advance, Dermot MacSweeney. ************************************************************** Dermot MacSweeney NMRC, Email: dsweeney at nmrc.ucc.ie Lee Maltings, Tel: +353 21 904...

Dear all, I would like to use the Levenberg-Marquardt algorithm for non-linear least-squares regression using function nls.lm. Can anybody help me to find a a way to compute confidence intervals on the fitted parameters as it is possible for nls (using confint.nls, which does not work for nls.lm)? Thank you for your help Michael

Hi, It seems to me that the most suitable method in R for curve-fitting is the use of nls, which uses a Gauss-Newton (GN) algorithm, while the use of the Levenberg-Marquardt (LM) algorithm does not seem to be very stressed in R. According to this [1] by Ripley, 'Levenberg-Marquardt is hardly competitive these days' which could imply the low emphasize on LM in R. The position of LM is, to some extend, confusing. Bonnans et al [2] introduce the trust-region-base...

...50 13 75 9 90 4 With the commercial software I obtain the following coefficients: Weibull Model: y=a-b*exp(-c*x^d) Coefficient Data: a = 1.31636909714E+001 b = 7.61325570579E+002 c = 2.82150000991E+002 d = -9.23838785044E-001 For fitting the Levenberg-Marquardt in R I'm using the following lines: pS<-list(a=1,b=1,c=1,d=1) model<-function(pS,xx){pS$a-pS$b*exp(-pS$c*xx^-pS$d)} resid<-function(observed,pS,xx){observed-model(pS,xx)} lin<-nls.lm(pS,resid,observed=Y,xx=X) Why I can't obtain the same results? Many thanks in advance, Fabio...

...ngular matrix `a' in solve I have found in the mailinglist "https://stat.ethz.ch/pipermail/r-help/2001-July/012196.html" that is if t he data are artificial. But the data are from my measurment. The commercial software "Origin V.6.1" solved this problem with the Levenberg-Marquardt algorithm how i want. The reference results are: a = 9.6899E-6, b = 0.00689, c = 2.72982 What are the right way or algorithm for me to solve this problem and what means this error with alg="plinear"? Thanks in advance. -- Weitersagen: GMX DSL-Flatrates mit Tempo-Garantie! Ab 4,99 Euro...

Hello, I want to fit some non linear models with the Levenberg-Marquardt algorithm. It doesn''t seem to exist any function to do this in R ( well, maybe one does, but I''m a new user, and the only documentation I have is "An introduction to R"). I''d like to know if this function exists, maybe throught an additionnal package. I'...

...ecommendable/useful to treat the logical cores like the physical cores? In our case we always assign one core only once to one domu to guarantee the performance to our customers. So the main question is if the performance differs between physical and logical cores noticeable. Kind regards, Jan Marquardt _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users

...ning I thought it would be the same as R's 'optim'. But then I looked at the definition of 'lsqnonlin' and I don't quite see how to make 'optim' to do the same thing. Does anyone have an idea? This is apart from the fact that I would like to use the Levenberg Marquardt algorithm which is not implemented in R (some discussion about this: http://tolstoy.newcastle.edu.au/R/help/00b/2492.html). Thank you! All the best, -- -- Jose Luis Aznarte M. http://decsai.ugr.es/~jlaznarte Department of Computer S...

Full_Name: Christian Marquardt Version: 2.1.0 OS: Linux (Redhat 9) Submission from: (NULL) (151.170.240.10) Following the advice of a reader of R-help, I would now like to submit this as a bug report: Say we have x = seq(1,3, by = 0.01) y = exp(x) Plotting and reversing linear axis is fine plot(x,y) plot(x,y, yli...

In the course of revising a paper I have had occasion to attempt to maximize a rather complicated log likelihood using the function nlm(). This is at the demand of a referee who claims that this will work better than my proposed use of a home- grown implementation of the Levenberg-Marquardt algorithm. I have run into serious hiccups in attempting to apply nlm(). If I provide gradient and hessian attributes to the returned function value (the ***negative*** of the log likelihood, since nlm() minimizes things) then nlm() wanders around for a very long time and reaches a highly sub...

...--------------------------------------------- Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzender des Aufsichtsrats: MinDir Dr. Karl Eugen Huthmacher Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender), Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------

...t Gauss-Newton. Since I am not an expert in the field of optimization, I am just conforming to what matlab documentation suggests, namely: "Algorithm used for the fitting procedure: Trust-Region -- This is the default algorithm and must be used if you specify coefficient constraints. Levenberg-Marquardt -- If the trust-region algorithm does not produce a reasonable fit, and you do not have coefficient constraints, you should try the Levenberg-Marquardt algorithm. Gauss-Newton --THIS ALGORITHM IS POTENTIALLY FASTER THAN THE OTHER ALGORITHMS, BUT IT ASSUMES THAT THE RESIDUALS ARE CLOSE TO ZERO. IT I...

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Am 06.02.2015 um 21:36 schrieb Guus Sliepen: > On Fri, Feb 06, 2015 at 09:01:21PM +0100, Flynn Marquardt wrote: > >> Analyzing a routing problem in a tinc net I found, that a declaration of >> a class-A subnet (x.0.0.0/8) in a host configuration file is ignored, e.g. >> >> Subnet = x.0.0.0/8 > [...] >> Splitting the subnet in two /9 subnets helps: >> >>...

Full_Name: Christian Marquardt Version: 2.2.1 OS: Linux Submission from: (NULL) (84.167.229.240) Hello, I believe this is a bug in the configuration / installation: When configuring R-2.2.1 using the Intel v9 Fortran compiler as default Fortran compiler and g++ as C++ compiler on a Suse 9.3 Linux, the configuration script fi...

...carry out in R, I would be grateful if you suggest to me some alternative procedure. I found that the "nls" function performs nonlinear least squares. The problem is that I do not want to implement the Gauss-Newton algorithm. In the worst case I would be contented with the "Levenberg-Marquardt" algorithm, if it is implemented in R. R nls's documentation mentions the "port" package and the ?nl 2sol? algorithm, but I could not find that package in the CRAN repository, so that I could read and judge whether that algorithm would be appropriate. Thank you very much in adv...

The package minpack.lm allows nonlinear regression problems to be addressed with a modification of the Levenberg-Marquardt algorithm based on the implementation of 'lmder' and 'lmdif' in MINPACK. Version 1.0-8 of the package is now available on CRAN. Changes in version 1.0-8 include: o possibility to obtain standard error estimates on the parameters via new methods for the generic functions...

The package minpack.lm allows nonlinear regression problems to be addressed with a modification of the Levenberg-Marquardt algorithm based on the implementation of 'lmder' and 'lmdif' in MINPACK. Version 1.0-8 of the package is now available on CRAN. Changes in version 1.0-8 include: o possibility to obtain standard error estimates on the parameters via new methods for the generic functions...

Hello, i am using currently rsync-2.6.0 with option --log-format=%f to produce a list of the transferred files. This list is then used to generate hard-links for backup-purposes. Now rsync sometimes generates messages like "file has vanished: ..." on STDOUT (_not_ STDERR) which breaks this processing. When using option -q there is no output at all. Is there any way to get a

Hi, i am using the output of --log-format=%f in a shell script to post-process the changed files. After an update from rsync 2.6.3 to 2.6.8 the script doesn't work correctly because it seems that since rsync 2.6.4 even directories appear in the log. Is there any way to have only the changed _files_ logged? BTW: What would be better to use: %n or %f? Regards, Markus

Dear All, In the past I have often used minpack (http://bit.ly/zXVls3) relying on the Levenberg-Marquardt algorithm to perform non-linear fittings. However, I have always dealt with a function of a single variable. Is there any difference if the function depends on two variables? To fix the ideas, please consider the function f(R,N)=(a/(log(2*N))+b)*R+c*N^d, where a,b,c,d are fit parameters. For a se...