Displaying 20 results from an estimated 3000 matches similar to: "constrOptim and function with additional parameters?"
2003 Oct 29
1
constrOptim doesn´t send arguments to optim!(?)
Hi,
I think that there something wrong with the 'constrOptim' max/minimization
function because she doesn?t send extra arguments to 'optim' call.
Fact: When I use optim in a f(x,theta)-like function, everything goes ok.
But using constrOptim with the same function leads to error...
Proof: Make a small change in the 'Rosenbrock Banana function' (taken from
the Examples
2004 Jul 14
0
Re: [R] constrOptim and function with additional parameters? (PR#7088)
I've moved this from r-help to r-bugs. If you reply, please be
careful that replies go to the right place: r-bugs if your comment is
specifically about the bug (and it contains the PR# in the subject
that will be added when this is cc'd to r-devel), r-devel if general
discussion, not both.
On Wed, 14 Jul 2004 10:01:45 -0400, "Roger D. Peng" <rpeng@jhsph.edu>
wrote :
2004 Jul 14
0
Re: [R] constrOptim and function with additional parameters? (PR#7089)
Okay, looking at the docs, then it's not a bug, since the "..."
argument is not actually documented as "other arguments passed to f or
grad". However, that *is* how it's document in `optim', so one can
see how this might cause some confusion.
Now, it's not clear to me which other arguments need to be passed to
`optim' except perhaps `hessian'. Am
2009 Nov 18
1
bug in '...' of constrOptim (PR#14071)
Dear all,
There appears to be a bug in how constrOptim handles ... arguments that
are suppose to be passed to optim, according to the documentation. This
means you can't get the hessian to be returned, for example (so this is
a real problem, and not just a question of mistaken documentation).
Looking at the code, it appears that a call to the user-defined f
includes the ..., when the ...
2011 Jun 24
4
How to capture console output in a numeric format
Hi,
I would like to know how to capture the console output from running an algorithm for further analysis. I can capture this using capture.output() but that yields a character vector. I would like to extract the actual numeric values. Here is an example of what I am trying to do.
fr <- function(x) { ## Rosenbrock Banana function
on.exit(print(f))
x1 <- x[1]
x2 <- x[2]
2008 Oct 22
1
optim bug/help?
In the documentation for 'optim' it gives the following function:
fr <- function(x) { ## Rosenbrock Banana function
x1 <- x[1]
x2 <- x[2]
100 * (x2 - x1 * x1)^2 + (1 - x1)^2
}
optim(c(-1.2,1), fr)
When I run this code I get:
$par
[1] 1.000260 1.000506
I am sure I am missing something but why isn't 1,1 a better answer? If I plug 1,1 in the function it seems
2023 Aug 05
1
feature request: optim() iteration of functions that return multiple values
For a solution that does not require any change to the original function
being optimized, the following one-liner could be used, which converts
existing functions to functions that return only the first element:
returnFirst <- function(fun) function(...) do.call(fun,list(...))[[1]]
Example:
fr <- function(x) { ## Rosenbrock Banana function
x1 <- x[1]
x2 <- x[2]
ans
2000 Mar 17
1
optim: problem with additional arguments (PR#493)
The R function "optim" fails when a function requires additional
arguments, if the option "hessian=T" is specified. I am using R Version
1.0.0 on Windows 98.
Here is an example of the Rosenbrock Banana function from the optim help
example, with the function and gradient modified to take an additonal
argument. Note that the call to optim works fine unless a hessian is
2023 Aug 03
3
feature request: optim() iteration of functions that return multiple values
Dear all,
I have used optim a lot in contexts where it would useful to be able to iterate function myfun that, in addition to the primary objective to be minimized ('minimize.me'), could return other values such as alternative metrics of the minimization, informative intermediate values from the calculations, etc.
myfun <- function()
{
...
return(list(minimize.me = minimize.me, R2 =
2004 Oct 05
1
constrOptim convergence
Hello, I got a question with the R function constrOptim.
>From the R help, it says that the return values of "constrOptim" are the
same as "optim". For the return value "convergence" of the function
"optim", the values should be 0, 1, 10, 51 and 52. See
http://www.maths.lth.se/help/R/.R/library/stats/html/optim.html
When I use constrOptim, I get
2006 Feb 01
1
output hessian matrix in constrOptim
Hi,
Is there any way to get the hessian matrix from the "constrOptim" function without supplying gradient function? Thanks.
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2009 Jun 03
1
Using constrOptim() function
I have a function myFunction(beta,x) where beta is a vector of coefficients
and x is a data frame (think of it as a matrix). I want to optimize the
function myFunction() by ONLY changing beta, i.e. x stays constant, with 4
constraints. I have the following code (with a separate source file for the
function):
rm(list=ls())
source('mySourceFile')
2011 Dec 20
1
constrOptim and problem with derivative
Dear List,
I am using constrOptim to solve the following
fr1 <- function(x) {
b0 <- x[1]
b1 <- x[2]
((1/(1+exp(-b0+b1))+(1/(1+exp(-b0)))+(1/(1+exp(-b0-b1)))))/3
}
As you can see, my objective function is
((1/(1+exp(-b0+b1))+(1/(1+exp(-b0)))+(1/(1+exp(-b0-b1)))))/3 and I would
like to solve for both b0 and b1.
If I were to use optim then I would derive the gradient of the
2010 Jun 17
2
constrOptim( ): conflict between help page and code
There is a contradiction between what the help page says and what constrOptim actually
does with the constraints. The issue is what happens on the boundary.
The help page says
The feasible region is defined by ?ui %*% theta - ci >= 0?,
but the R code for constrOptim reads
if (any(ui %*% theta - ci <= 0))
stop("initial value not feasible")
The following example
2008 Jan 18
1
constrOptim with method SANN
Hi Everyone,
I'm trying to minimize a function using constrOptim with
the simulated annealing method SANN.
If I understand constrOptim well, it basically passes most
of its arguments to optim while somehow enforcing the constraints.
My problem is, that since SANN does not need gradients,
when using optim with SANN, the gr argument of optim is
used to specify a function to create the next
2011 Dec 21
1
constrOptim and further arguments
Dear List,
I have the code below, where I am using the constrained optimisation
package, 'constrOptim.nl' to find the values of two values, b0 and b1.
I have no problems when I enter further variable information DIRECTLY into
the functions, fn, and heq. In this instance I require fn to have -0.0075
appended to it, and in the case of heq, h[1] has -0.2.
library(alabama)
2009 Sep 11
1
constrOptim parameters
Dear R wizards: I am playing (and struggling) with the example in the
constrOptim function. simple example. let's say I want to constrain my
variables to be within -1 and 1. I believe I want a whole lot of
constraints where ci is -1 and ui is either -1 or 1. That is, I have 2*N
constraints. Should the following work?
N=10
x= rep(1:N)
ci= rep(-1, 2*N)
ui= c(rep(1, N), rep(-1, N))
2012 Dec 07
1
Error using constrOptim in constraint definition
Hello,
I'm trying to run constrOptim. It returns to me an error about the fact that constraints arguments (ui and ci) are non compatibles:
> optout= constrOptim(startparams, f=ImpulseSS, grad=grImpulse, ui=UI, ci=CI, data=gexp[k,], t=t)
Error in ui %*% theta : non-conformable arguments
I would like to point out that I can calculate that product in the command line:
> UI %*%
2007 Aug 01
1
constrOptim
Hi,
I'm having trouble using the constrOptim function to generate the
9-component vector argmin of the function ELfsds:
ELfsds <- function(pvechat){
LG=0
for(i in 1:9){
LG=LG+log(pvechat[i])
}
return(-LG)
}
with accompanying gradient function:
gradfunc <- function(thetavec){
g=1/(9*thetavec)
return(g)
}
The constraints on the optimization problem are:
1 - components of
2010 Mar 17
1
constrOptim - error: initial value not feasible
Hello at all,
working with a dataset I try to optimize a non-linear function with
constraint.
test<-read.csv2("C:/Users/Herb/Desktop/Opti/NORM.csv")
fkt<- function(x){
a<-c(0)
s<-c(0)
#Minimizing square error
for(j in 1:107){
s<-(test[j,2] - (x[1] * test[j,3]) - (x[2] * test[j,4]) - (x[3]*test[j,5]) -
(x[4]*test[j,6]) - (x[5]*test[j,7]))^2
a<- a+s}
a<-as.double(a)