Displaying 12 results from an estimated 12 matches similar to: "nmle question"
2005 Nov 16
6
nlme question
I am using the package nlme to fit a simple random effects (variance
components model)
with 3 parameters: overall mean (fixed effect), between subject
variance (random) and
within subject variance (random).
I have 16 subjects with 1-4 obs per subject.
I need a 3x3 variance-covariance matrix that includes all 3 parameters
in order to
compute the variance of a specific linear
2003 Jul 25
0
Memory explosion, plotting nmle grouped data object
Hi
I am using R 1.7.1 on RH linux 9.0
> sum(unlist(lapply(ls(),function(x)object.size(get(x)))))/1024^2
[1] 2.424263
so I am not using much memory (I have a gig of ram on my machine)
now in nlme
> gtest<-groupedData(log(X8)~Time|sub,all[,c(names(all)[1:9],"X8")],outer=~A*B)
> object.size(gtest)/1024
[1] 59.98438
> plot(gtest,outer=~Dose*chem,key=FALSE,asp=.5)
Plotting
2001 Dec 03
0
problems with nmle
Following the Indomethicin example in Pinheiro & Bates, chapter 6,
page 277 etc, coming to the following comand:
fm2Indom.nlme <- update( fm1Indom.nlme,
random = pdDiag(A1 + lrc1 + A2 ~ 1) )
debugging nlme gives the following output:
Browse[1]> n
debug: modelResid <- ~eval(model, data.frame(data, getParsNlme(plist,
fmap, rmapRel, bmap, groups, beta, bvec, b, level,
2012 Jun 12
0
Specifying spatial correlation Form in nmle
Dear R users,
I'm applying a correlation structure in a mixed model (nmle function) to
control for spatial correlation between land parcels that are adjacent to
each other. I generated X,Y coordinates in ArcGIS for each land parcel and
used them in the correlation form like this:
test.exp<-corExp(1, form = ~ X + Y)
test.exp<- Initialize(test.exp,dataset)
However, the correlation
2006 Nov 16
0
nmle for time of structural change?
Hi, All:
Does 'nlme' require the nonlinear function to be differentiable?
I'm fitting structural change models to many related time series, and
I'd like to improve the estimates of the change point times through some
type of pooling. Unfortunately, I've so far been unable to get 'nlme'
to work for me. The following toy example is the closest I've come
2005 Nov 09
0
source of "susbcript out of bounds error" in nmle
A few days ago I posted a question to this discussion group concerning
to origin of an error message < subscript out of bounds > while using
the nonlinear mixed model (nlme) function in R with a self-starting
function. Thanks for those who responded. This posting is to explain
what (I think) it causing the error.
Pinheiro & Bates (2000, pages 342-347) describe how to construct a
2007 Oct 17
2
nmle: gnls freezes on difficult case
Hi,
I am not sure this is a bug but I can repeat it, The functions and data
are below.
I know this is nasty data, and it is very questionable whether a 4pl
model
is appropriate, but it is data fed to an automated tool and I would
have hoped for an error. Does this repeat for anyone else?
My details:
> version
_
platform i686-pc-linux-gnu
2006 Nov 06
0
problem with survreg and anova function
Hi,
I make a weibull survival regression using suvreg function. Bu when I try to
get the P values from anova, it give me NAs:
I'm using R 2.4.0 and survival 2.29
Look:
m <- survreg(Surv(tempo,censor)~grupo*peso)
anova(m)
Df Deviance Resid. Df -2*LL P(>|Chi|)
NULL NA NA 148 966.6416 NA
grupo -2 25.6334407 146 941.0081 NA
2007 Feb 02
0
problem with survreg and anova function
Hi,
I make a weibull survival regression using suvreg function. Bu when I try to
get the P values from anova, it give me NAs:
I'm using R version 2.4.0 Patched (2006-11-25 r39997) and survival 2.30
library
Look:
m <- survreg(Surv(tempo,censor)~grupo*peso)
anova(m)
Df Deviance Resid. Df -2*LL P(>|Chi|)
NULL NA NA 148 966.6416 NA
grupo
2017 Jun 01
0
Reversing one dimension of an array, in a generalized case
??
> z <- array(1:24,dim=2:4)
> all.equal(f(z,3),f2(z,3))
[1] "Attributes: < Component ?dim?: Mean relative difference: 0.4444444 >"
[2] "Mean relative difference: 0.6109091"
In fact,
> dim(f(z,3))
[1] 2 3 4
> dim(f2(z,3))
[1] 3 4 2
Have I made some sort of stupid error here? Or have I misunderstood
what was wanted?
Cheers,
Bert
Bert Gunter
2017 Jun 01
3
Reversing one dimension of an array, in a generalized case
Here is an alternative approach using apply(). Note that with apply() you are reversing rows or columns not indices of rows or columns so apply(junk, 2, rev) reverses the values in each column not the column indices. We actually need to use rev() on everything but the index we are interested in reversing:
f2 <- function(a, wh) {
dims <- seq_len(length(dim(a)))
dims <-
2010 Sep 03
1
Fourteen patches to speed up R
I've continued to work on speeding up R, and now have a collection of
fourteen patches, some of which speed up particular functions, and
some of which reduce general interpretive overhead. The total speed
improvement from these patches is substantial. It varies a lot from
one R program to the next, of course, and probably from one machine to
the next, but speedups of 25% can be expected in