Displaying 13 results from an estimated 13 matches similar to: "term.formula error when updating an nls object"
2011 Sep 03
2
problem in applying function in data subset (with a level) - using plyr or other alternative are also welcome
Dear R experts.
I might be missing something obvious. I have been trying to fix this problem
for some weeks. Please help.
#data
ped <- c(rep(1, 4), rep(2, 3), rep(3, 3))
y <- rnorm(10, 8, 2)
# variable set 1
M1a <- sample (c(1, 2,3), 10, replace= T)
M1b <- sample (c(1, 2,3), 10, replace= T)
M1aP1 <- sample (c(1, 2,3), 10, replace= T)
M1bP2 <- sample (c(1, 2,3), 10, replace= T)
2006 Jan 19
1
nls profiling with algorithm="port" may violate bounds (PR#8508)
[posted to R-devel, no discussion:
resubmitting it as a bug, just so it gets
logged appropriately]
Sorry to report further difficulties with
nls and profiling and constraints ... the problem
this time (which I didn't check for in my last
round of testing) is that the nls profiler doesn't
seem to respect constraints that have been
set when using the port algorithm.
See test code
2012 Apr 10
1
compare two matrices
Dear Members,
I have two estimated transition matrices and I want to compare them.
In fact I want to check the hypothesis if they come from the same process.
I tried to look for some test but all I found was independence test of
contingency tables.
The following code shows that the usual chi-squared test statistic does
not follow chisq distribution.
MCRepl <- 5000
khi12 <- rep(0,MCRepl)
2011 May 04
0
Fwd: simple question
Sorry I had typo in previous email,
this typo corrected version:
Dear R experts
I have simple question, please execuse me:
#example data, the real data consists of 20000 pairs of variables
K1 <- c(1,2,1, 1, 1,1); K2 <- c(1, 1,2,2, 1,2); K3 <- c(3, 1, 3, 3, 1, 3)
M1a <- rep( K1, 100); M1b <- rep(K2, 100)
M2a <- rep(K1, 100); M2b <- rep(K1, 100)
M3a <- rep(K1, 100); M3b
2007 Feb 13
1
lme4/lmer: P-Values from mcmc samples or chi2-tests?
Dear R users,
I have now tried out several options of obtaining p-values for
(quasi)poisson lmer models, including Markov-chain Monte Carlo sampling
and single-term deletions with subsequent chi-square tests (although I
am aware that the latter may be problematic).
However, I encountered several problems that can be classified as
(1) the quasipoisson lmer model does not give p-values when
2014 Mar 17
5
LD50
Quiero comparar varias dosis letales 50% (LD50) usando análisis probit. He
seguido un ejemplo que viene en paquete DRC, pero no obtengo el resultado
esperado. Lo que quiero es saber si las LD50s, son diferentes y si la
diferencias son estadísticamente significativas.
Gracias de antemano.
José Arturo
e-mail. jafarfan@uady.mx <grejon@uady.mx>
e-mail alterno. jafarfan@gmail.com
2006 Jan 17
0
nls profile with port/constraints
Sorry to report further difficulties with
nls and profiling and constraints ... the problem
this time (which I didn't check for in my last
round of testing) is that the nls profiler doesn't
seem to respect constraints that have been
set when using the port algorithm.
See test code below ...
If I can I will try to hack the code, but I will
probably start by redefining my function with
2011 Jun 30
0
CCF of two time series pre-whitened using ARIMA
Hi all,
I have two time series that I would like to correlate but as they are
autocorrelated, I am "pre-whitening" them first by fitting ARIMA models,
then correlating their residuals....as described in
https://onlinecourses.science.psu.edu/stat510/?q=node/75
However, http://www.stat.pitt.edu/stoffer/tsa2/Rissues.htm discusses some
issues with ARIMA in R. In particular, for issue 2, if
2009 Apr 15
2
AICs from lmer different with summary and anova
Dear R Helpers,
I have noticed that when I use lmer to analyse data, the summary function
gives different values for the AIC, BIC and log-likelihood compared with the
anova function.
Here is a sample program
#make some data
set.seed(1);
datx=data.frame(array(runif(720),c(240,3),dimnames=list(NULL,c('x1','x2','y'
))))
id=rep(1:120,2); datx=cbind(id,datx)
#give x1 a
2009 Feb 23
1
Follow-up to Reply: Overdispersion with binomial distribution
THANKS so very much for your help (previous and future!). I have a two
follow-up questions.
1) You say that dispersion = 1 by definition ....dispersion changes from 1
to 13.5 when I go from binomial to quasibinomial....does this suggest that
I should use the binomial? i.e., is the dispersion factor more important
that the
2) Is there a cutoff for too much overdispersion - mine seems to be
2003 Jul 16
1
The two chisq.test p values differ when the contingency table is transposed! (PR#3486)
Full_Name: Tao Shi
Version: 1.7.0
OS: Windows XP Professional
Submission from: (NULL) (149.142.163.65)
> x
[,1] [,2]
[1,] 149 151
[2,] 1 8
> c2x<-chisq.test(x, simulate.p.value=T, B=100000)$p.value
> for(i in (1:20)){c2x<-c(c2x,chisq.test(x,
simulate.p.value=T,B=100000)$p.value)}
> c2tx<-chisq.test(t(x), simulate.p.value=T, B=100000)$p.value
> for(i in
2008 Jan 10
1
general linear hypothesis glht() to work with lme()
Hi,
I am trying to test some contrasts, using glht() in
multcomp package on fixed effects in a linear mixed
model fitted with lme() in nlme package. The command I
used is:
## a simple randomized block design,
## type is fixed effect
## batch is random effect
## model with interaction
dat.lme<-lme(info.index~type, random=~1|batch/type,
data=dat)
glht(dat.lme, linfct = mcp(type
2005 Dec 21
9
question about changejournal
Hi,
I''ve got a newbie question--sorry if this is covered elsewhere, I parsed
through the archives for awhile and didn''t see it.
I''d like to listen for whenever a file is renamed (e.g. foo.txt -> foo.old)
and then magically change it back. This sounds odd, but I''m working with a
stubborn application and this will actually make things work nice.
So, if I do: