[R] Help about nlminb function

[Jonathan P Daily]

Your function is evaluating to Inf. Is this expected behavior? I don't 
know what starting values you are using, but it looks like the initial 
values evaluate to Inf. If this is also true for values near your initial 
conditions then I am not surprised the optimization returns initial 
values.

Try changing parametres[,3]
--------------------------------------
Jonathan P. Daily
Technician - USGS Leetown Science Center
11649 Leetown Road
Kearneysville WV, 25430
(304) 724-4480
"Is the room still a room when its empty? Does the room,
 the thing itself have purpose? Or do we, what's the word... imbue it."
     - Jubal Early, Firefly

kamel gaanoun <kamel.gaanoun at gmail.com> wrote on 12/15/2010 09:22:57 AM:

> [image removed] 
> 
> Re: [R] Help about nlminb function
> 
> kamel gaanoun 
> 
> to:
> 
> Jonathan P Daily
> 
> 12/15/2010 09:23 AM
> 
> Cc:
> 
> r-help, r-help-bounces
> 
> I appologize for the lack of information in my previous mail, but it
> is my first one.
> 
> Yes  I red -in part- the Port documentation to learn what does the 
> message X-convergence (3) mean.
> 
> so this is my nlminb and the results :
> 
> res1<-nlminb(parametres[,3], V, lower=c(rep(0.01, 18), rep(0.01, 3),
> rep(-Inf, 6)), upper=c(rep(Inf, 18), rep(0.99, 3), rep(Inf, 6)), 
> control = list(maxit=1000) )
> 
> 
> Results : > res1
> $par
>  [1] 1.0000000 1.0000000 1.0000000 1.0000000 1.0000000 1.0000000 
1.0000000
>  [8] 1.0000000 1.0000000 1.0000000 1.0000000 1.0000000 1.0000000 
1.0000000
> [15] 1.0000000 1.0000000 1.0000000 1.0000000 0.6899225 0.7993528 
0.6480687
> [22] 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
> 
> $objective
> [1] Inf
> 
> $convergence
> [1] 0
> 
> $message
> [1] "X-convergence (3)"
> 
> $iterations
> [1] 1
> 
> $evaluations
> function gradient 
>        2       27 
> 
> 
> So as you see, it stops after just one iteration but it is converging.
> 
> 
> Thanks

> 2010/12/15 Jonathan P Daily <jdaily at usgs.gov>
> How are we supposed to help you if we have no idea how you are using it?
> Did you read the PORT documentation? Did you look at the control
> parameters outlined in the function help page? Often times for me a 
return
> of the initial conditions is an issue with either inappropriate 
tolerance
> or having variables on very different scales.
> 
> Since you did not follow the posting guide (important part *'d below), 
my
> only suggestion is to ?nlminb
> --------------------------------------
> Jonathan P. Daily
> Technician - USGS Leetown Science Center
> 11649 Leetown Road
> Kearneysville WV, 25430
> (304) 724-4480
> "Is the room still a room when its empty? Does the room,
>  the thing itself have purpose? Or do we, what's the word... imbue it."
>     - Jubal Early, Firefly
> 
> r-help-bounces at r-project.org wrote on 12/15/2010 08:53:39 AM:
> 
> > [image removed]
> >
> > [R] Help about nlminb function
> >
> > kamel gaanoun
> >
> > to:
> >
> > r-help
> >
> > 12/15/2010 08:56 AM
> >
> > Sent by:
> >
> > r-help-bounces at r-project.org
> >
> > Hi Everyone,
> >
> >   Can anyone help me resolve a problem that i'm having with nlminb. 
The
> > problem is that it stops after just one iteration and returns the same
> > values as "start" ones.
> >
> >
> > Thank you very much for your help.
> >
> >
> > Sincerely.
> >
> >
> > --
> > Kamel Gaanoun
> > (+33) (0)6.76.04.65.77
> >
> >    [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> 
******************************************************************************
> > PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> 
******************************************************************************

> 
> 
> 
> -- 
> Kamel Gaanoun
> (+33) (0)6.76.04.65.77