Displaying 20 results from an estimated 10000 matches similar to: "Two Questions on R (call by reference and pre-compilation)"
2004 Feb 24
5
Nonlinear Optimization
Hi,
I have been brought back to the "R-Side" from MatLab. I have used R in
graduate econometrics but only for statistics and regression (linear and
nonlinear). But now I need to run general nonlinear optimization.
I know about the add-in quadprog but my problem is not QP. My problem is a
general nonlinear (obj funct) with linear constraints.I know about the "ms"
and
2010 May 08
2
meaning of "<<-"
Hi,
In my memory, "<<-" means assigning via a pointer or alias. But this is
not officially defined in "R Language Definition". Could anybody help
for the clarification? Thank you very much!
Bests,
Ruihong
2009 Feb 05
2
Non-linear optimisation
Hi there,
I have a piece of Matlab code I use to optimise a trding strategy. If there
are any Matlab/R specialists out there, I would appreciate your help in
doing the exact same optimisation in R.
I suspect I would use nlm() in R but am not sure where to define my
constraints.
I have attached my Matlab code below for reference.
Many thanks.
Constraints
function [c,ceq]=TriskellConstraints(X)
2006 Dec 08
1
fmincon equivalent in R
Dear all R users,
I am wondering if there are any function for Constraint optimization in R.
Especially i am looking for a R - equivalent of "fmincon" function in
MATLAB.
Thanks and regards,
Arun
[[alternative HTML version deleted]]
2010 May 05
3
Latex and Stangle()
Hi,
I'm using the Sweave and I would like include codes of the R
in my LaTeX file.
I extracts the R code with Stangle (), whose name is
Relatorio.R but I can't include it
in the Latex file as an appendix.
Suggests?
Thanks,
--------------------------------------
Silvano Cesar da Costa
Departamento de Estat?stica
Universidade Estadual de Londrina
Fone: 3371-4346
2006 Nov 26
2
Quadratic Optimization
Hi,
I need to solve an optimization problem in R having linear objective function and quadratic constraints(number of variables is around 80). What are the possible choices to do this in R.
optim() function only allows box constrained problems. Is it possible in nlm()? Or please tell me if there is any other routine.
Thanks
Amit
2010 May 05
0
R-help Digest, Vol 87, Issue 5
Unsubscribe
-----Original Message-----
From: r-help-request at r-project.org
Date: Wed, 05 May 2010 12:00:09
To: <r-help at r-project.org>
Subject: R-help Digest, Vol 87, Issue 5
Send R-help mailing list submissions to
r-help at r-project.org
To subscribe or unsubscribe via the World Wide Web, visit
https://stat.ethz.ch/mailman/listinfo/r-help
or, via email, send a message with subject
2025 Mar 28
3
Problem with minimization that I failed to understand
Hi Duncan,
Thanks for your comment, I agree with that.
But, how it can be justified that an Optimizer gives a result which is
inferior to the starting value? At most, resulting value can remain at the
same level, isnt it?
On Fri, 28 Mar 2025 at 14:34, Duncan Murdoch <murdoch.duncan at gmail.com>
wrote:
> I haven't run your code, but since Kendall correlation is based on
>
2025 Mar 28
1
Problem with minimization that I failed to understand
I haven't run your code, but since Kendall correlation is based on
ranks, your Fn is probably locally constant with jumps when the ranks
change. That's a really hard kind of function to maximize, and the
algorithm used by fmincon is not appropriate to do it.
Sorry, but I don't know if there is an R function that can do
constrained discrete maximization.
Duncan Murdoch
On
2025 Mar 27
1
Problem with minimization that I failed to understand
?s 19:36 de 27/03/2025, Daniel Lobo escreveu:
> My code is to minimize the objective function
>
> therefore, shouldnt I expect that
>
> StartingValue = c(0.12, 0.04, 0.07, 0.03, 0.06, 0.07, 0.07, 0.04, 0.09,
> 0.08, 0.02, 0.02, 0.03, 0.06, 0.02, 0, 0.07, 0.05, 0.02, 0.02, 0.02)
> Fn(q1$par) < Fn(StartingValue)
> ## FALSE
>
> Below is the corrected code that can
2003 Jun 26
0
nonlinear constraint optimization function in R?
Dear all,
I am looking for a R-function that performs nonlinear constraint
optimization (where the objective function and the
constraints are allowed to be nonlinear).
More specifically, I am trying to figure out whether there
is an equivalent function of NAG fortran library' "E04UCF" or matlab's
"fmincon" in R.
Any help is greatly appreciated.
Thank you,
Sunduz
2025 Mar 27
1
Problem with minimization that I failed to understand
My code is to minimize the objective function
therefore, shouldnt I expect that
StartingValue = c(0.12, 0.04, 0.07, 0.03, 0.06, 0.07, 0.07, 0.04, 0.09,
0.08, 0.02, 0.02, 0.03, 0.06, 0.02, 0, 0.07, 0.05, 0.02, 0.02, 0.02)
Fn(q1$par) < Fn(StartingValue)
## FALSE
Below is the corrected code that can be reproduced:
MyDat = structure(list(c(50L, 0L, 0L, 50L, 75L, 100L, 50L, 0L, 50L, 0L,
25L,
2025 Mar 28
1
Problem with minimization that I failed to understand
?s 13:59 de 28/03/2025, Daniel Lobo escreveu:
> Hi Duncan,
>
> Thanks for your comment, I agree with that.
>
> But, how it can be justified that an Optimizer gives a result which is
> inferior to the starting value? At most, resulting value can remain at the
> same level, isnt it?
>
> On Fri, 28 Mar 2025 at 14:34, Duncan Murdoch <murdoch.duncan at gmail.com>
2025 Mar 27
2
Problem with minimization that I failed to understand
Hi,
I have below minimization problem
MyDat = structure(list(c(50L, 0L, 0L, 50L, 75L, 100L, 50L, 0L, 50L, 0L,
25L, 50L, 50L, 75L, 75L, 75L, 0L, 75L, 75L, 75L, 0L, 25L, 75L,
75L, 0L, 75L, 100L, 0L, 25L, 100L), c(75L, 0L, 0L, 50L, 100L,
50L, 75L, 75L, 100L, 25L, 0L, 25L, 100L, 0L, 50L, 0L, 25L, 25L,
100L, 75L, 0L, 0L, 0L, 50L, 0L, 75L, 75L, 0L, 50L, 25L), c(50L,
0L, 0L, 0L, 100L, 25L, 0L, 0L,
2025 Mar 27
1
Problem with minimization that I failed to understand
?s 18:35 de 27/03/2025, Daniel Lobo escreveu:
> Hi,
>
> I have below minimization problem
>
>
> MyDat = structure(list(c(50L, 0L, 0L, 50L, 75L, 100L, 50L, 0L, 50L, 0L,
> 25L, 50L, 50L, 75L, 75L, 75L, 0L, 75L, 75L, 75L, 0L, 25L, 75L,
> 75L, 0L, 75L, 100L, 0L, 25L, 100L), c(75L, 0L, 0L, 50L, 100L,
> 50L, 75L, 75L, 100L, 25L, 0L, 25L, 100L, 0L, 50L, 0L, 25L, 25L,
>
2005 Dec 06
7
R is GNU S, not C.... [was "how to get or store ....."]
======= 2005-12-06 22:16:17 伳侜佋佢伬伌佇伵佒佇佇伌伒伬仯伜=======
>Martin Maechler a 侀crit :
>
>> please, please, these trailing ";" are *so* ugly.
>> This is GNU S, not C (or matlab) !
>>
>> but I'll be happy already if you could
>> drop these ugly empty statements at the end of your lines...
>
>May I disagree ?
>I find missing ";" at
2011 Oct 01
7
Poor performance of "Optim"
I used to consider using R and "Optim" to replace my commercial packages:
Gauss and Matlab. But it turns out that "Optim" does not converge
completely. The same data for Gauss and Matlab are converged very well. I
see that there are too many packages based on "optim" and really doubt if
they can be trusted!
--
View this message in context:
2007 May 19
2
What's wrong with my code ?
I try to code the ULS factor analysis descrbied in
ftp://ftp.spss.com/pub/spss/statistics/spss/algorithms/ factor.pdf
# see PP5-6
factanal.fit.uls <- function(cmat, factors, start=NULL, lower = 0.005,
control = NULL, ...)
{
FAfn <- function(Psi, S, q)
{
Sstar <- S - diag(Psi)
E <- eigen(Sstar, symmetric = TRUE, only.values = TRUE)
e <- E$values[-(1:q)]
e <-
2007 Sep 07
2
Matlab's lsqnonlin
Hi! I'm translating some code from Matlab to R and I found a problem.
I need to translate Matlab's function 'lsqnonlin'
(http://www-ccs.ucsd.edu/matlab/toolbox/optim/lsqnonlin.html) into R,
and at the beginning 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
2006 Jun 12
1
r's optim vs. matlab's fminsearch
Hi,
I'm having a problem converting a Matlab program into R. The R code works
almost all the time, but about 4% of the time R's optim function gets stuck
on a local minimum whereas matlab's fminsearch function does not (or at
least fminsearch finds a better minimum than optim). My understanding is
that both functions default to Nelder-Mead optimization, but what's
different about