Displaying 20 results from an estimated 5000 matches similar to: "how to get code of a .Internal() function?"
2003 Jul 09
2
.Internal(optim)
> hi all,
> I am using optim. I am getting the following error message:
>
> Error in optim(par = start.vals[, h], fn = post.func.pois, gr = post.grad.
> pois, :
> L-BFGS-B needs finite values of fn
>
> If I look at optim typing '> optim' it seems that the error comes from
> inside .Internal(optim), so I wonder how can I see the code for .Internal(
2008 Nov 19
1
How to look within .Internal ?
In the optim() function there is a syntax :
res <- .Internal(optim(par, fn1, gr1, method, con, lower,
Here how can I see the inside-codes of ".Internal" function ?
Regards,
--
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2006 Apr 13
1
bus error on calling nmmin
Hi,
I'm trying to get a toy program making use of nmmin to run
successfully. I've gotten to the point of compiling. However, when I
attempt to run my executable, I guess a bus error. I see that someone
else has asked about using nmmin before
<http://tolstoy.newcastle.edu.au/R/help/06/03/23944.html>, but I
haven't come across any replies.
Is there some documentation on how to
2006 Mar 29
1
calling R's optimization routines from C
Hi,
I have read R's Writing Extensions manual and am still confused about how to
use some of the routines there when I call from C. Specifically, I am writing a
little test function which I will optimize using the nmmin function which
underlies R's optim() with Nelder-Mead. I guess I wonder what library/header
files I should be using. I was using R_ext/Applic.h and linking with libR but I
2011 Mar 18
1
[Patch suggestion] Adding 3rd arg to tempfile() to set extension
The other day I was working on an example which used tempfile() to create
file for use by the graphics device. And while I love tempfile()---as it is
portable and clever and the files get cleaned by R and all that---I noticed
one missing feature I would like to see: beside a starting name pattern, and
an optional directory, an 'file extension' argument would be nice to have.
As e.g. in
2010 Mar 05
2
Improved Nelder-Mead algorithm - a potential replacement for optim's Nelder-Mead
Hi,
I have written an R translation of C.T. Kelley's Matlab version of the Nelder-Mead algorithm. This algorithm is discussed in detail in his book "Iterative methods for optimization" (SIAM 1999, Chapter 8). I have tested this relatively extensively on a number of smooth and non-smooth problems. It performs well, in general, and it almost always outperforms optim's
2017 Dec 31
1
Order of methods for optimx
Dear R-er,
For a non-linear optimisation, I used optim() with BFGS method but it
stopped regularly before to reach a true mimimum. It was not a problem
with limit of iterations, just a local minimum. I was able sometimes to
reach better minimum using several rounds of optim().
Then I moved to optimx() to do the different optim rounds automatically
using "Nelder-Mead" and
2010 Feb 08
2
evolution of Nelder-Mead process
Dear list,
I am looking for an R-only implementation of a Nelder-Mead process that can find local maxima of a spatially distributed variable, e.g. height, on a spatial grid, and outputs the coordinates of the new point during each evaluation. I have found two previous threads about this topic, and was wondering if something similar has been implemented since those messages were posted.
Thank
2009 Oct 10
2
Nelder-Mead with output of simplex vertices
Greetings!
I want to follow the evolution of a Nelder-Mead function
minimisation (a function of 2 variables). Hence each simplex
will have 3 vertices.
Therefore I would like to have a function which can output
the coordinates of the 3 vertices after each new simplex
is generated. However, there seems to be no way (which I can
detect) of extracting this information from optim() (the
2012 May 01
2
Define lower-upper bound for parameters in Optim using Nelder-Mead method
Dear UseRs,
Is there a way to define the lower-upper bounds for parameters fitted by
optim using the Nelder-Mead method ?
Thanks,
Arnaud
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2006 Jan 17
1
how can i locate the source code of a module quickly?
I have dowloaded the Source Code of R,and I want to know the process of
chi-sqared test,but how can I found it?
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2005 Nov 15
1
An optim() mystery.
I have a Master's student working on a project which involves
estimating parameters of a certain model via maximum likelihood,
with the maximization being done via optim().
A phenomenon has occurred which I am at a loss to explain.
If we use certain pairs of starting values for optim(), it
simply returns those values as the ``optimal'' values, although
they are definitely not
2010 Sep 04
3
How can I fixe convergence=1 in optim
Hi R users,
I am using the optim funciton to maximize a log likelihood function. My
code is as follows:
p<-optim(c(-0.2392925,0.4653128,-0.8332286, 0.0657, -0.0031, -0.00245,
3.366, 0.5885, -0.00008,
0.0786,-0.00292,-0.00081, 3.266, -0.3632, -0.000049, 0.1856,
0.00394, -0.00193, -0.889, 0.5379, -0.000063,
0.213, 0.00338, -0.00026, -0.8912, -0.3023, -0.000056), f,
2007 Jun 22
2
fitCopula
I am using R 2.5.0 on windows XP and trying to fit copula. I see the
following code works for some users, however my code crashes on the
chol. Any suggestions?
> mycop <- tCopula(param=0.5, dim=8, dispstr="ex", df=5)
> x <- rcopula(mycop, 1000)
> myfit <- fitCopula(x, mycop, c(0.6, 10), optim.control=list(trace=1),
method="Nelder-Mead")
2007 Jan 03
1
optim
Hi!
I'm trying to figure out how to use optim... I get some really strange results, so I guess I got something wrong.
I defined the following function which should be minimized:
errorFunction <- function(localShifts,globalShift,fileName,experimentalPI,lambda)
{
lambda <- 1/sqrt(147)
# error <- abs(errHuber(localShifts,globalShift,
#
2012 Oct 23
1
help using optim function
Hi, am very new to R and I've written an optim function, but can't get it to
work
least.squares.fitter<-function(start.params,gr,low.constraints,high.constraints,model.one.stepper,data,scale,ploton=F)
{
result<-optim(par=start.params,method=c('Nelder-Mead'),fn=least.squares.fit,lower=low.constraints,upper=high.constraints,data=data,scale=scale,ploton=ploton)
2023 Aug 13
4
Noisy objective functions
While working on 'random walk' applications, I got interested in
optimizing noisy objective functions. As an (artificial) example, the
following is the Rosenbrock function, where Gaussian noise of standard
deviation `sd = 0.01` is added to the function value.
fn <- function(x)
(1+rnorm(1, sd=0.01)) * adagio::fnRosenbrock(x)
To smooth out the noise, define another
2009 Nov 30
3
Question about output from optim
Dear R-users,
I am trying to port to R something that I wrote in Matlab to perform model
parameter optimization using the Nelder-Mead simplex method (fminsearch). I
read the help on ?optim (which seems to be the way to go) as well as a bunch
of posts on the topic, but I would like to make sure about something before
I spend to much time trying to reproduce something that is not possible. The
2012 Nov 03
2
optim & .C / Crashing on run
Hello,
I am attempting to use optim under the default Nelder-Mead algorithm for
model fitting, minimizing a Chi^2 statistic whose value is determined by a
.C call to an external shared library compiled from C & C++ code.
My problem has been that the R session will immediately crash upon starting
the simplex run, without it taking a single step.
This is strange, as the .C call itself works,
2008 Mar 11
1
messages from mle function
Dears useRs,
I am using the mle function but this gives me the follow erros that I
don't understand. Perhaps there is someone that can help me.
thank you for you atention.
Bernardo.
> erizo <- read.csv("Datos_Stokes_1.csv", header = TRUE)
> head(erizo)
EDAD TALLA
1 0 7.7
2 1 14.5
3 1 16.9
4 1 13.2
5 1 24.4
6 1 22.5
> TAN <-