Displaying 20 results from an estimated 1000 matches similar to: "Fast Two-Dimensional Optimization"
2010 Sep 14
2
How to uncompress a gz file in R
Dear Fellows,
I would like to know how to uncompress a gz file at the R console. I could
not find out any help from the R-help archive.
Thanks for your great help.
Best Regards,
Wonsang You
-----
--
Wonsang You
Special Lab Non-Invasive Brain Imaging
Leibniz Institute for Neurobiology
http://www.ifn-magdeburg.de
--
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2010 Sep 16
2
How to combine matrix and vector
Dear fellows,
I am a novice in R. I would like to combine a matrix and a vector. Assume
that we have the matrix a and the vector b with same length of column.
a<-matrix(seq(1:10),nrow=2,ncol=5,byrow=TRUE)
a=
1 2 3 4 5
6 7 8 9 10
b<-t(c(11,12,13,14,15))
b=
11 12 13 14 15
Then, I want to combine a and b as follows.
c=
1 2 3 4 5
6 7 8 9
2010 Oct 13
2
How to fix error in the package 'rgenoud'
Dear R user fellows,
I would like to ask you about the package 'rgenoud' which is a genetic
optimization tool.
I ran the function 'genoud' with two variables to be minimized by the
following command.
result<-genoud(fn,nvars=2,starting.values=c(0.5,0),
pop.size=1000, max.generations=10, wait.generations=3)
Then, I had the following error message.
Error in
2011 Feb 26
1
2D Convolution Function
Dear R-Helpers,
I want to try the 2D (two-dimensional) convolution in R.
For example, let us we have the following kernel and data.
kernel <- (1,2,3,2,1)
data <- array(1:100, dim=c(10,10))
I know the function 'convolve' only for one-dimensional convolution, but it
is just for a 1D sequence.
Is there any function for 2D convolution?
For theory, please refer to the following link:
2011 Aug 29
3
gradient function in OPTIMX
Dear R users
When I use OPTIM with BFGS, I've got a significant result without an error
message. However, when I use OPTIMX with BFGS( or spg), I've got the
following an error message.
----------------------------------------------------------------------------------------------------
> optimx(par=theta0, fn=obj.fy, gr=gr.fy, method="BFGS",
>
2010 Aug 31
4
How to Adaptively Set Up the Coordinate Range of Multiple Graphs in One Figure
Hi, R-Helpers,
I would like to ask about multiple graphs in one figure. I tried to execute
the following codes.
xlim <- c(1,100)
ylim <- c(1,4)
plot(NA, xlim=xlim, ylim=ylim)
> x <- c(1:100)
for(j in seq(1,10,by=1)) {
y <- j*x^2+log(j)
lines(x, y)
}
In the above codes, I had to arbitrarily set up the coordinate range of the
figure in advance before
2011 Feb 08
1
Simulation of Multivariate Fractional Gaussian Noise and Fractional Brownian Motion
Dear R Helpers,
I have searched for any R package or code for simulating multivariate
fractional Brownian motion (mFBM) or multivariate fractional Gaussian noise
(mFGN) when a covariance matrix are given. Unfortunately, I could not find
such a package or code.
Can you suggest any solution for multivariate FBM and FGN simulation? Thank
you for your help.
Best Regards,
Ryan
-----
Wonsang You
2011 Mar 23
2
R helps win competitions
DeaR ComRades,
This is a quote from a News article in Science's 11-February issue, about competitions to model data:
"For Chris Raimondi, a search-engine expert based in Baltimore, Maryland, and winner of the HIV-treatment competition, the Kaggle contest motivated him to hone his skills in a newly learned computer language called R, which he used to encode the winning data model.
2011 Feb 02
1
Error of 'memory not mapped' in ff Package with VirtualBox
Dear R Helpers,
I would like to report on an error in the ff package here.
The ff package is an R package which enables us to store large data on disk
systematically and have fast access to the database.
I used the package in Linux as a guest OS of VirtualBox, and executed the
following commands.
library(ff)
2011 Nov 17
2
RV: Reporting a conflict between ADMB and Rtools on Windows systems
De: Rubén Roa
Enviado el: jueves, 17 de noviembre de 2011 9:53
Para: 'Users@admb-project.org'
Asunto: Reporting a conflict between ADMB and Rtools on Windows systems
Hi,
I have to work under Windows, it's a company policy.
I've just found that there is a conflict between tools used to build R packages (Rtools) and ADMB due to the need to put Rtools compiler's
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!
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2010 Jan 29
1
Plotmath: suprscript on scalable delimiter?
ComRades,
How do you put a superscript on a scalable delimiter?
I want to put 'b' as the power of the expression in the following plot:
t <- 1:25
K <- 0.2
y <- ((1-exp(-K*t))/(1-exp(-K*t)*exp(K)))^3
plot(t,y,"l",main="K=0.2, b=3")
text(15,5,expression(bgroup("(",frac(1-e^-Kt,1-e^-Kt*e^K),")")))
Plotmath examples in demo(plotmath) do not
2011 Mar 31
1
Simple lattice question
DeaR ComRades,
require(lattice)
data <- data.frame(SP=sort(rep(as.factor(c('A','B','C','D','E')),12)),
x=rpois(60,10),
y=rep(c(rep(0,4),rep(10,4),rep(20,4)),5),
z=rep(1:4,15))
xyplot(x~y|SP,data=data,groups=z,layout=c(2,3),pch=1:4,lty=1:4,col='black',type='b')
How do I put a legend
2010 Jun 21
1
Problem with package installation
Dear ComRades,
I am having the "wrong MD5 checksums" error with every package I try to install.
It happened with R 2.11.0, then I updated to R 2.11.1, same thing.
sessionInfo()
R version 2.11.1 (2010-05-31)
i386-pc-mingw32
locale:
[1] LC_COLLATE=Spanish_Spain.1252 LC_CTYPE=Spanish_Spain.1252 LC_MONETARY=Spanish_Spain.1252
[4] LC_NUMERIC=C
2011 Mar 23
1
R helps win competitions
DeaR ComRades,
This is a quote from a News article in Science's 11-February issue, about competitions to model data:
"For Chris Raimondi, a search-engine expert based in Baltimore, Maryland, and winner of the HIV-treatment competition, the Kaggle contest motivated him to hone his skills in a newly learned computer language called R, which he used to encode the winning data model.
2011 Feb 14
9
¿Mejor formato para insertar gráficos de R en Word?
Hola, ¿qué tal?
Me han pedido que genere unos gráficos para insertarlos en un
docuemento de Word. Yo suelo generar gráficas en formato PNG, pero me
han dicho que "quedan mal". Y yo apenas sé nada de Word.
¿Cuál sería el formato gráfico más adecuado en este caso?
Un saludo y muchas gracias,
Carlos J. Gil Bellosta
http://www.datanalytics.com
2011 Jun 22
1
AIC() vs. mle.aic() vs. step()?
I know this a newbie question, but I've only just started using AIC for
model comparison and after a bunch of different keyword searches I've
failed to find a page laying out what the differences are between the
AIC scores assigned by AIC() and mle.aic() using default settings.
I started by using mle.aic() to find the best submodels, but then I
wanted to also be able to make comparisons
2010 Jul 07
9
problema con file
Hola. Tengo un archivo de texto con formato Ansi en Windows que lo
quiero convertir en una serie temporal pero cuando lo trato de hacer
con el siguiente comando:
out <- read.zoo(readLines(con <- file("log2.log",
encoding="UCS-2LE")),FUN = as.chron)
Me da los siguientes errores:
Error en file(file, "rt") : no se puede abrir la conexión
Además: Mensajes de
2011 May 20
8
Building Custom GUIs for R
I am looking to build simple GUIs based on the R codes I have. The main
objective is to hide the scary R codes from non-programming people and make
it easier for them to try out different inputs.
For example,
1. The GUI will have means to upload a csv file which will be read by the R
code.
2. A button to preprocess data (carried out by a R function behind)
3. A button to build some models
2010 Sep 24
1
(sin asunto)
Podrías mandar un summary de tu conjunto de datos o un str para ver por que
no puede estimar esos efectos, también sería útil el resultado de
with(tusdatos, table(Landscape,Crop,Position))
Gabriela