Displaying 20 results from an estimated 300 matches similar to: ": BIC for gls models"
2003 Jan 22
1
: Trellis plot
Hi all,
I would be grateful if anyone could help me with the following. I am using
nlme library and I am trying to do a trellis plot with an outer factor, but
I have an error message which I can't understand.
Here is the code :
> mydata <- groupedData(y ~ x | warren/rabbit, outer= ~ treatment,
data=mydata)
> plot(mydata)
# I obtain a plot with all rabbits displayed individually and
2003 Jul 24
1
: performing marginal tests to glm objects
Dear all,
I wonder if it is possible to obtain marginal tests for effects in generalized linear models. Indeed, the anova function produces sequential tests and it doesn't have any "type" argument to specify that we would like marginal tests instead, as in the similar anova function for lme objects.
Thanks a lot for your help!
Eve CORDA
Office national de la chasse et de la faune
2002 Sep 11
2
fitting a linear mixed effects model
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2007 Sep 07
1
negative value for AIC and BIC
Hi all,
I obtained negative values for AIC and BIC criteria for a particular
model that I have
developped...
I don't remember to have negative values for these crietria for others
applications, so I am a
little suprised... Could anyone tell me if something is wrong or his
conclusion concerning my model?
Best regards,
Olivier.
2019 Jan 12
2
Polybench llvm's IR -fopenmp
Hi all,
I'm trying to get the llvm's IR from the source code of Polybench (OMP) https://github.com/cavazos-lab/PolyBench-ACC/tree/master/OpenMP.
I noticed a considerable difference between the IR generated using clang -emit-llvm -fopenmp and clang -emit-llvm:
* using the -fopenmp flag I get a simplified IR in which I read a single basic block where I can highlight a llvm.memcpy
2007 May 01
2
Concepts question: environment, frame, search path
Folks:
I'd appreciate if someone could straighten me out on a few concepts which
are described a bit ambiguously in the docs.
1. data.frame:
----------------
Refan p84: 'A data frame is a list of variables of the same length with
unique row names, given class "data.frame".'
I probably don't need to point out how opaque that is!
Anyhow, key question: Some places in
2004 Dec 19
1
PBIB datataset
I'm looking at Pinheiro & Bates "Mixed-Effects Models in
S and S-PLUS" at the moment. Several datasets are used,
one of which is called "PBIB" (a partially balanced
incomplete block design).
All the other datasets can be found somewhere or other in R.
However, I cannot locate PBIB, and it does not seem to
be mentioned in the latest edition of the R Full Reference
2007 Apr 11
1
Programming Problem (for loop, random # control, 3 dimentional graph)
Dear List,
This is just a programming problem which i cannot seem
to figure out. I am trying to get a set of power from
a test (say, kolmogorov smirnov) out of a distribution
(say, G-K distribution) as follows. I am trying to
reduce to pain of writing the whole set of data points
(p# below) using "for" loop. However, I seem to have
some problem in it as the output "M" does not
2012 Apr 05
4
Appropriate method for sharing data across functions
In trying to streamline various optimization functions, I would like to have a scratch pad
of working data that is shared across a number of functions. These can be called from
different levels within some wrapper functions for maximum likelihood and other such
computations. I'm sure there are other applications that could benefit from this.
Below are two approaches. One uses the <<-
2003 Jul 18
3
question about formulating a nls optimization
Dear list,
I'm migrating a project from Matlab to R, and I'm
facing a relatively complicated problem for nls. My
objective function is below:
>> objFun <- function(yEx,xEx,tEx,gamma,theta,kappa){
yTh <- pdfDY(xEx,tEx,gamma,theta,kappa)
sum(log(yEx/yTh)^2)
}
The equation is yTh=P(xEx,tEx) + noise.
I collect my data in:
>> data <-
2008 Aug 20
3
bug in lme4?
Dear all,
I found a problem with 'lme4'. Basically, once you load the package 'aod' (Analysis of Overdispersed Data), the functions 'lmer' and 'glmer' don't work anymore:
library(lme4)
(fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy))
(gm1 <- glmer(cbind(incidence, size - incidence) ~ period + (1 | herd),
family = binomial, data
2004 Oct 31
2
Obtaining fitted model information
Dear list,
I am brand new to R and using Dalgaard's (2002) book Introductory Statistics with R (thus, some of my terminology may be incorrect).
I am fitting regression models and I want to use Hurvich and Tsai's AICC statistic to examine my regression models. This penalty can be expressed as: 2*npar * (n/(n-npar-1)).
While you can obtain AIC, BIC, and logLik, I want to impose the AICC
2003 May 20
3
a quick Q about memory limit in R
Hello, there,
I got this error when i tried to run " data.kr <- surf.gls(2, expcov,
data, d=0.7);"
"Error: cannot allocate vector of size 382890 Kb
Execution halted"
My data is 100x100 grid.
the following is the summary of "data":
> summary(data);
x y z
Min. : 1.00 Min. : 1.00 Min. :-1.0172
1st Qu.: 26.00
2010 Sep 15
1
optim with BFGS--what may lead to this, a strange thing happened
Dear R Users
on a self-written function for calculating maximum likelihood probability (plz
check function code at the bottom of this message), one value, wden, suddenly
jump to zero. detail info as following:
w[11]=2.14
lnw =2.37 2.90 3.76 ...
regw =1.96 1.77 1.82 ....
wden=0.182 0.178 0.179...
w[11]=2.14
lnw=2.37 2.90 3.76 ...
regw =1.96 1.77 1.82 ....
wden=0.182
2008 Mar 27
1
A faster way to compute finite-difference gradient of a scalar function of a large number of variables
Hi All,
I would like to compute the simple finite-difference approximation to the
gradient of a scalar function of a large number of variables (on the order
of 1000). Although a one-time computation using the following function
grad() is fast and simple enough, the overhead for repeated evaluation of
gradient in iterative schemes is quite significant. I was wondering whether
there are
2008 Dec 19
0
What BIC is calculated by 'regsubsets'?
The function 'regsubsets' appears to calculate a BIC value that is
different from that returned by the function 'BIC'. The latter is
explained in the documentation, but I can't find an expression for the
statistic returned by 'regsubsets'.
Incidentally, both of these differ from the BIC that is given in Ramsey
and Schafer's, The Statistical Sleuth. I assume
2010 Sep 07
5
question on "optim"
Hey, R users
I do not know how to describe my question. I am a new user for R and write the
following?code for a dynamic labor economics?model and use OPTIM to get
optimizations and parameter values. the following code does not work due to
the?equation:
?? wden[,i]<-dnorm((1-regw[,i])/w[5])/w[5]
where w[5]?is one of the parameters (together with vector a, b and other
elements in vector
2010 Nov 15
1
comparing levels of aggregation with negative binomial models
Dear R community,
I would like to compare the degree of aggregation (or dispersion) of
bacteria isolated from plant material. My data are discrete counts
from leaf washes. While I do have xy coordinates for each plant, it
is aggregation in the sense of the concentration of bacteria in high
density patches that I am interested in.
My attempt to analyze this was to fit negative binomial
2018 Apr 17
1
Minor glitch in optim()
Having worked with optim() and related programs for years, it surprised me
that I haven't noticed this before, but optim() is inconsistent in how it
deals with bounds constraints specified at infinity. Here's an example:
# optim-glitch-Ex.R
x0<-c(1,2,3,4)
fnt <- function(x, fscale=10){
yy <- length(x):1
val <- sum((yy*x)^2)*fscale
}
grt <- function(x, fscale=10){
nn
2004 Jul 16
1
Does AIC() applied to a nls() object use the correct number of estimated parameters?
I'm wondering whether AIC scores extracted from nls() objects using
AIC() are based on the correct number of estimated parameters.
Using the example under nls() documentation:
> data( DNase )
> DNase1 <- DNase[ DNase$Run == 1, ]
> ## using a selfStart model
> fm1DNase1 <- nls( density ~ SSlogis( log(conc), Asym, xmid, scal ),
DNase1 )
Using AIC() function:
>