Displaying 20 results from an estimated 600 matches similar to: "Constrained Optimization, a full example"
2009 Jun 17
0
Curve fit a nonlinear equation with box constraints: success, many thanks!
Dear R Helper Community!
Thank you for all your help and suggestions.
For your reference and any future person searching the archives, here is the
solution that did what I wanted it to do.
As background, my goal was to find the coefficients for the following
equation form:
y ~ c1 * x1 * x2 ^ -c2 *x3 ^ c3
where y, x1, x2, and x3 are observed data, and
c1, c2 and c3 are regression
2009 Dec 29
2
pass functions and arguments to function
Hi,
I wonder how to pass several functions and their arguments as arguments to
a function. For example, the main function is
f = function(X ) {
process1(X)
...
process2(X)
}
I have a few functions that operate on X, e.g. g1(X, par1), g2(X, par2),
g3(X, par3). par1, par2 and par3 are parameters and of different types. I
would like to pass g1, g2, g3 and their arguments to f and g1,
2009 Dec 29
1
(no subject)
Hi,
I wonder how to pass several functions and their arguments as arguments to
a function. For example, the main function is
f = function(X ) {
process(X)
...
process(X)
}
I have a few functions that operate on X, e.g. g1(X, par1), g2(X, par2),
g3(X, par3). par1, par2 and par3 are parameters and of different types.
2009 May 20
1
SEM:Standard error of std.coef estimates?
Hi,
I am currently working with the sem package in R, to create pathway
diagrams. Id like to use the standardized path coeffcients. To get these, I
use std.coef. However, using this yields only the standardized coefficients,
but does not give me the standard error. Does someone know how to get
std.coef to show the standard error of the standardized path coefficients as
well?
Thanks,
Bastiaan
2011 Feb 04
2
vegan and sweave using xtable
Dear all,
Using:
library(vegan)
data(BCI)
mod <- radfit(BCI[1,])
mod
RAD models, family poisson
No. of species 93, total abundance 448
par1 par2 par3 Deviance AIC BIC
Null 39.5261 315.4362 315.4362
Preemption 0.042797 21.8939 299.8041 302.3367
Lognormal 1.0687 1.0186 25.1528 305.0629 310.1281
2006 Feb 08
1
expand.grid without expanding
Dear list,
I've recently came across a problem that I think I've solved and that I wanted
to share with you for two reasons:
- Maybe others come across the same problem.
- Maybe someone has a much simpler solution that wants to share with me ;-)
The problem is as follows: expand.grid() allows you to generate a data.frame
with all combinations of a set of values, e.g.:
>
2005 Mar 02
1
Rounding parameter values in genoud(), Rgenoud package
I would like to limit the significant figures of the calibrated
parameters determined by genoud() in the Rgenoud package. Below is some
example output, where column 1 is model run number, columns 2-7 are the
parameter values, and columns 8-12 are model fit statistics. I would
like genoud to internally limit parameters to 4 decimal places as shown
in this output. It is clear that the function is
2012 Feb 13
0
Error from GNLS (undefined columns selected)
Dear R-helpers,
I'm a new R-user and I was trying to gain some experience with the GNLS function of the NLME package.
This is an extract from my dataset (it's a 432x6 data.frame) called "input", in the first column I have the values that I need to fit, while the remaining columns are input variables for the theoretical model, the function "mymodel" (which returns a
2012 Jun 06
1
error calling Winbugs using R2WinBugs to run a multi-level model
Dear all,
I'm calling Winbugs (1.4.3) through R2WinBugs (2.1-18 coda_0.14-7) to
fit a switching random walk model, but come up with an instant trap
with the log only displaying 'check('.
I will paste the trap with session info below; I'd be very grateful
for any ideas.
Couple of leads:
1. I presume the problem relates to the r package itself or the way I
call bugs(), because I
2007 Oct 30
2
flexible processing
Hello,
unfortunately, I don't know a better subject. I would like to be very flexible
in how to process my data.
Assume the following dataset:
par1 <- seq(0,1,length.out = 100)
par2 <- seq(1,100)
fac1 <- factor(rep(c("group1", "group2"), each = 50))
fac2 <- factor(rep(c("group3", "group4", "group5", "group6"), each =
2007 Dec 19
2
recode based on filter
Hi, I have a data frame DATA, which (simplified of course) looks like this:
know1 = c("Y","N","N","Y","N","N","Y","Y","N")
par1=c(1,4,5,3,3,2,3,3,5)
know2 = c("Y","Y","N","Y","N","N","N","Y","Y")
2011 Apr 07
2
Two functions as parametrs of a function.
Hi R users:
I'm trying to make a function where two of the parameters are
functions, but I don't know how to put each set of parameters for
each function.
What am I missing?
I try this code:
f2<-function(n=2,nsim=100,fun1=rnorm,par1=list(),fun2=rnorm,par2=list()){
force(fun1)
force(fun2)
force(n)
p1<-unlist(par1)
p2<-unlist(par2)
force(p1)
force(p2)
2005 Dec 05
1
how to save output all together
Dear R users:
I have a problem about catch the value from function.
I have following two functions (part):
sbolus1 <- function()
{
.......
for( i in 1:Subject) {
kel<-par1
Vd<-par2
PKindex<-sbolus1.out(PKtime,kel,Vd,defun,par1,par2,Dose,i)
}
savefile(PKindex)
}
sbolus1.out<-function(PKtime,kel,Vd,defun,par1,par2,Dose,i)
{
time<-PKtime$time
2009 Jun 16
2
Trouble with optim on a specific problem
Hello!
I am getting the following errors when running optim() [I tried optim() with
3 different methods as you can see]:
Error in optim(c(0.66, 0.999, 0.064), pe, NULL, method = "L-BFGS-B") :
objective function in optim evaluates to length 6 not 1
> out <- optim( c(0.66, 0.999, 0.064), pe, NULL, method = "Nelder-Mead")
Error in optim(c(0.66, 0.999, 0.064),
2004 Dec 14
1
Multiple options for a package
Hi R-devel,
I am facing a situation where the number of options I would like to propose
to the user is somewhat big (and could easily increase more and more as I
will code up a little more - even coming to a point where an user should be
able to implement his own options).
What we have to handle options is the couple:
options(par=value) and getOption("par")
I was aking myselft what
2005 Nov 22
1
problem with "parse"
Hi there again,
I have a problem with the "parse"-command.
First of all, I show you in a simplified way, what I am trying to do and what "R" answers:
> test
[1] "u.g$par1, u.g$par2"
> mode(test)
[1] "character"
> ausdruck <- parse(text = test)
Error in parse(file, n, text, prompt) : syntax error in "u.g$par1,"
2000 Dec 29
0
Is this a bug? Having cex!=1 before setting par(mai=) gives strange line spacings.
width <- 7
height <- 5
# create whatever device type
# and have cex=1 before setting par(mai=)
windows(width=width, height=height, rescale="R")
oldmai <- par("mai")
par(cex=1)
par(mai=oldmai)
plot.new()
par(usr=c(0,2,0,2))
par(cex=2)
par1 <- par()
text(1,1,"there is hardly anything i know for sure\nneither of the future nor of the past\nnor should i know what
2008 Aug 26
1
no output when run densityplot...
Hi,
I have downloaded a R script from
http://www.wessa.net/rwasp_edauni.wasp#output.
This script produces a densityplot graphic, amongst others, when is
executed from the web page.
However, when I run it in my machine the *densityplot* function produces
any output, I mean a blank graphic.
But, it's interesting if I run the following lines in the R interactive
console:
> y <-
2011 Mar 15
1
Problem with nls.lm function of minpack.lm package.
Dear R useRs,
I have a problem with nls.lm function of minpackl.lm package.
I need to fit the Van Genuchten Model to a set of data of Theta and hydraulic conductivity with nls.lm function of minpack.lm package.
For the first fit, the parameter estimates keep changing even after 1000 iterations (Th)
and
I have a following error message for fit of hydraulic conductivity (k);
Reason for
2004 Feb 11
6
lapply and dynamically linked functions
Hi all,
I'm trying to use lapply on a list with the following command:
out<-lapply(mylist,myfun,par1=p,par2=d) (1)
where
myfun<-function(x,par1,par1) {.....} (2)
now this function is in fact a wrapper for some Fortran code I have
written so I think this might be the problem. When I call lapply() as in
(1) I get the following message:
Error in get(x,