Displaying 20 results from an estimated 100 matches similar to: "HELP with NLME"
2007 Apr 15
1
Fit sem model with intercept
Hi - I am trying to fit sem model with intercepts. Here is what I have in my model.
Exogeneous vars: x1 (continous), x2 (ordinal), x3 (ordinal), x4(continuous)
Endogeneous vars: y1 (continuous), y2 (ordinal), y3 (ordinal)
SEM model:
x1 -> eta1; x2 -> eta1; x3 -> eta2; x4 -> eta2; eta1 -> y1, eta1 -> y2, eta2 -> y2, eta2 -> y3
However, in these arrow models, I
2004 Feb 03
1
Error in f(x, ...) : subscript out of bounds
R-Listers:
I am doing a quasi-maximum likelihood estimation and I get a "subscript
out of bound" error message, Typically I would think this means that a
subscript used in the function is literally out of bounds however I don't
think this is the case. All I change in the code is a constant, that is
hard-wired in (not data dependent and not parameter dependent),
furthermore,
2008 Nov 26
1
Request for Assistance in R with NonMem
Hi
I am having some problems running a covariate analysis with my
colleage using R with the NonMem program we are using for a graduate
school project. R and NonMem run fine without adding in the
covariates, but the program is giving us a problem when the covariate
analysis is added. We think the problem is with the R code to run the
covariate data analysis. We have the control stream, R code
2002 Feb 11
0
profile
I am running 1.3.1 on a Windows (NT 4.0) machine. I've fit a nonlinear
model intended to predict crop yield from nutrient information, and want to
use the profile function. If I type say,
profile(simparj.fm)
I get the following error message:
"Error in prof$getProfile(): number of iterations exceeded maximum of
5.25515e-308"
I used the profiler function to profile simparj,fm step
2009 Apr 21
1
How to compare parameters of non linear fitting curves
Hi,
I'm using a non linear model to fit experimental survival curves.
This model describes the fraction of "still active" experiments as a
function of time t as follows:
f(t)=(1+exp(-etaD*cD)) / (1+exp(etaD(t-cD)))
Moreover, when experiments are still active, they may change of state
(from 0 to 1). But they may fall inactive before changing their state
(their state still
2005 Mar 09
1
Trouble with mixreg
Dear All
I am trying to estimate a mixture of regression and get the
following error using the mixreg package:
Error in y - yhat : non-conformable arrays
The instruction I used were:
x <- as.matrix(LRHUN)
y <- as.matrix(LRINTER)
TS <- list(list(beta=c(3.0,1.0),sigsq=1,lambda=0.4),
list(beta=c(0.0,1.0),sigsq=1,lambda=0.6))
prova <- mixreg(x,y, ncomp=2, theta.start=TS)
2007 Jul 26
3
substituting dots in the names of the columns (sub, gsub, regexpr)
Dear R users,
I have the following two problems, related to the function sub, grep,
regexpr and similia.
The header of the file(s) I have to import is like this.
c("y (m)", "BD (g/cm3)", "PR (Mpa)", "Ks (m/s)", "SP g./g.", "P
(m3/m3)", "theta1 (g/g)", "theta2 (g/g)", "AWC (g/g)")
To get rid of spaces and
2009 Jan 08
3
NY Times article
Sorry if this is spam, but I couldn't see it having popped up on the list
yet.
http://www.nytimes.com/2009/01/07/technology/business-computing/07program.html?emc=eta1
Anand
[[alternative HTML version deleted]]
2004 Feb 26
2
Structural Equation Model
Hello all!
I want to estimate parameters in a MIMIC model. I have one latent
variable (ksi), four reflexive indicators (y1, y2, y3 and y4) and four
formative indicators (x1, x2, x3, x4). Is there a way to do it in R? I
know there is the SEM library, but it seems not to be possible to
specify formative indicators, that is, observed exogenous variables
which causes the latent variable.
Thanks,
2009 Apr 22
0
Rép : How to compare parameters of non linear fitting curves - COMPLETE REPLY -
Oups, I sent the email by error, as I was still writing my reply…
Spencer,
Le 22-avr.-09 à 03:33, spencerg a écrit :
> Is your first model a special case of the second with eta1 = 0?
> If yes, what about using 2*log(likelihood ratio) being approximately
> chi-square?
Yes, the first model is a special case of the second with eta1=0â¦
Could you give me more explanation about
2010 Apr 08
2
I can´t run the example shown in the inline package
I want to run some R script using the inline package (which allows to create
and run inline C++ code in my humble understanding).
So, after loading the required packages and copy and paste the example that
runs C code (in the Reference Manual as a PDF), I have a compilation error.
Any body has ever tried this inline package?
--
View this message in context:
2017 Nov 24
0
Using bartMachine with the caret package
Dave Langer in this video https://www.youtube.com/watch?v=z8PRU46I3NY
uses the titanic data as an example of using caret to create xgbTree
models. The caret train() function has a tuneGrid parameter which
takes a list set up like so:
tune.grid <- expand.grid(eta = c(0.05, 0.075, 0.1),
nrounds = c(50, 75, 100),
max_depth = 6:8,
2005 Aug 12
3
General expression of a unitary matrix
Hi, all,
Does anybody got the most general expression of a unitary matrix?
I found one in the book, four entries of the matrix are:
(cos\theta) exp(j\alpha); -(sin\theta)exp(j(\alpha-\Omega));
(sin\theta)exp(j(\beta+\Omega)); (cos\theta) exp(j\beta);
where "j" is for complex.
However, since for any two unitary matrices, their product should also
be a unitary matrix. When I
2007 Feb 22
0
Error in solve.default
I am trying to run the following function (a hierarchical bayes linear
model) and receive the error in solve.default. The function was
originally written for an older version of SPlus. Can anyone give me some
insights into where the problem is?
Thanks
R 2.4.1 on MAC OSX 2mb ram
Mark Grant
markg at uic.edu
> attach(Aspirin.frame)
> hblm(Diff ~ 1, s = SE)
Error in solve.default(R, rinv)
1999 Sep 16
1
MS executables for my libraries
An executable version 0.6 of my libraries is now available at
www.luc.ac.be/~jlindsey/rcode.html
This works with MS R0.64.2 and appears possibly to work with R65.0.
There is a serious problem with the Fortran compiler as some of the
examples for elliptic and carma crash it. These same examples do not crash
R63.0 with the library executables of Jan 99. I am releasing this anyway
because of the
2012 Mar 23
0
Fixing error variance in a path analysis to model measurement error in scales using sem package
Hi!
I want to construct a path analysis model that can account for measurement
error in totally aggregated parcels, which refer to parcels where all of
the items in a scale are summed or averaged. If I am not mistaken, Bollen
(1989) advocates the following formula for computing the error variance of
each parcel:
(1−α(parcel))×variance(parcel),
such that α refers to Cronbach's alpha, which
2012 Nov 15
1
hessian fails for box-constrained problems when close to boundary?
Hi
I am trying to recover the hessian of a problem optimised with
box-constraints. The problem is that in some cases, my estimates are very
close to the boundary, which will make optim(..., hessian=TRUE) or
optimHessian() fail, as they do not follow the box-constraints, and hence
estimate the function in the unfeasible parameter space.
As a simple example (my problem is more complex though,
2008 Apr 07
0
Translating NLMIXED in nlme
Dear All,
reading an article by Rodolphe Thiebaut and Helene Jacqmin-Gadda ("Mixed
models for longitudinal
left-censored repeated measures") I have found this program in SAS
proc nlmixed data=TEST QTOL=1E-6;
parms sigsq1=0.44 ro=0.09 sigsq2=0.07 sigsqe=0.18 alpha=3.08 beta=0.43;
bounds $B!](B1< ro < 1, sigsq1 sigsq2 sigsqe >= 0;
pi=2*arsin(1);
mu=alpha+beta*TIME+a i+b i*TIME;
2008 Mar 15
1
again with polr
hello everybody
solved the problem with summary, now I have another one
eg I estimate
> try.op <- polr(
> as.ordered(sod.sit.ec.fam) ~
> log(y) +
> log(1 + nfiglimin) +
> log(1 + nfiglimagg) +
> log(ncomp - nfiglitot) +
> eta +
> I(eta^2) +
>
2010 Jun 15
1
MANOVA proportion of variance explained
Hello everybody
After doing a MANOVA on a bunch of data, I want to be able to make some comment on the amount of variation in the data that is explained by the factor of interest. I want to say this in the following way: XX% of the data is explained by A.
I can acheive something like what I want by doing the following:
X <- structure(c(9, 6, 9, 3, 2, 7), .Dim = as.integer(c(3,