similar to: optim works on command-line but not inside a function

Dear R community, I'm fitting a complex mixed-effects model that requires numerous iterations and function evaluations. I note that nlminb accepts a list of control parameters, including eval.max. Is there a way to change the default eval.max value for nlminb when it is being called from lme? Thanks for any thoughts, Andrew -- Andrew Robinson Department of Mathematics and Statistics

I'm trying to convert an S-Plus program to R.  Since I'm a SAS programmer I'm not facile is either S-Plus or R, so I need some help.  All I did was convert the underscores in S-Plus to the assignment operator <-.  Here are the first few lines of the S-Plus file:   sshc _ function(rc, nc, d, method, alpha=0.05, power=0.8,              tol=0.01, tol1=.0001, tol2=.005, cc=c(.1,2),

Hello R, I am looking for non-parametric simulation in IRT. Is there any IRT package that does non-parametric simulation? helen L [[alternative HTML version deleted]]

Hola, I am trying to isolate the memory leak I suspect in a mailman installation ? I found: http://blogs.sun.com/sanjeevb/date/200506 It gives an error: god at irt-smtp-02:~ 9:21am 65 # ./memleak.d 10312 dtrace: failed to compile script ./memleak.d: line 3: probe description pid10312:libc.so.1:malloc:entry does not match any probes I am on SunOS 5.10 Generic_127112-07 i86pc i386 i86pc Are

Hello, I want to compute Wainer et al's augmented subscore(2001) using IRT but I can't find any packages or relevant code. There is a 'subscore' package in R, but I think it only gives functions to calculate augmented subscores using CTT(classical test theory). Is there other package or code to compute subscores using IRT? If it is not, is there any plan to develop it in

Hello All, I was wondering how I can get the overall Pearson chi^2 test of model fit with its df and p value in the LTM package for the 2PL models. Thanks, -- Davood Tofighi Department of Psychology Arizona State University [[alternative HTML version deleted]]

I have no idea, but Google pointed me to this https://cran.r-project.org/web/packages/subscore/index.html Hth Ulrik "Hyunju Kim" <asdfg4882 at yonsei.ac.kr> schrieb am Di., 15. Mai 2018, 07:21: > > > > Hello, > > > > I want to compute Wainer et al's augmented subscore(2001) using IRT but I > can't find any packages or relevant code. > >

Using the grm function (graded response IRT model) in the ltm package I receive the following error: Error: subscript out of bounds for several scales I'd like to examine. Here's a small example that if run a few times will likley produce the error at least once ch<-array(round(runif(50,1,5)),c(10,5)) grm(ch,start.val="random") ## or

Hi my friends, I'm very new to R and need your help. I used R and ltm package for item response theory (IRT) modeling. I also need to compute differential item function (DIF) for IRT models. I searched the archive but basically found nothing. Could you help me find some sources about handling DIF of IRT? Many thanks in advance! Feng

hello R: we have a two-parameter IRT simulation code. The goal is to generate a response matrix.But the "for" part doesn't run. we don't know what is wrong with it. Thanks so much~~~ I <- 10 J <- 5 response <- matrix(0, 10, 5) pij <- function(a,b,theta) { a <- rnorm(J, 0.8, 0.04) a b <- rnorm(J, 0, 1) b theta <- rnorm(I, 0,1) theta for( i in 1:I ) { for(

Hello colleagues, I am a novice with R and am stuck with an analysis I am trying to conduct. Any suggestions or feedback would be very much appreciated. I am analyzing a data set of psi (ESP) ganzfeld trials. The response variable is binary (correct/incorrect), with a 25% base rate. I've looked around the documentation and other online resources and cannot find how I can correct for

Dear list, I want to run a statistical program (using its .exe file) from R by writing a script. I know there are some packages that call WinBUGS, Mplus etc. form R. I just want to call the .exe extension of this program and run several times writing a code in R. Thus, I want to have the output inside R. I just don't know where to start. Does anyone have any idea about that? Is there a

hello R, This is about simulation in psychomtrics in IRT in R. I want to simulate b parameters(item difficulty) with moments of fixed values of mean, st.d, skewness and kurtosis. Is there any specific IRT package in R with those functions to control those moments? I have seen other programs that can control mean and st.d but not skewness and kurtosis. Thank you, helen L [[alternative HTML

Hello, I''m wondering if someone might be able to offer me a solution to the following problem that has so far stumped me. I''m trying to get the distinct months (and years) from a date field to display as a list in a view. For example, there might be a number of records stored with dates in the table ''headlines'': name date record1 21-09-2008 record2

Hi all, Could anyone tell me if there is some package that fits any Item Response Model (further the ltm package)? Regards, Caio --------------------------------- [[alternative HTML version deleted]]

Hi my friends, I have an issue with ability estimates when running GRM of IRT. I have responses from 242 subjects but got 183 ability estimates. Below is what I did to get the estimates. 1) I have a csv file "P1.csv" and I imported it into R and loaded the "ltm" package by doing: p1<-read.table("P1.csv",header=TRUE,sep=",") library(ltm) 2) I

Hello, thank you very much for your previous answers about the C++ code. I am interested in the application of the Gibbs Sampler in the IRT models, so in the function MCMCirt1d and MCMCirtkd. I've found the C++ source codes, as you suggested, but I cannot find anything about the Gibbs Sampler. All the files are for the Metropolis algorithm. Maybe I am not able to read them very well, by the

I am using 32 bit R - 2.15.2 version and working on package ltm. The program does not give me any warning message when I run tpm command for a dataset. If run tpm command for the same dataset in 64-bit R 2.15.1 version, I get the warning message shown below. Can someone suggest why is no warning message being generated by 32-bit R? Or is it being generated but not getting printed? Which function

Hello All, I'm trying to print specific row and column for Observed_Scores matrix, however, when I execute the command "Observed_Scores[1,1]", I get the message "Error in Observed_Scores[1, 1] : incorrect number of dimensions". Could you please help and let me know where is the mistake? Here is my program: library(ltm) library(psych) # Settting the working directory

Hello All, I'm trying to run a one-dimenional irt model using the packages MCMC and coda on a rather large set of roll-call voting data with many missing observations. Here's a sample of the code: Post10<- MCMCirt1d (Italy10, burnin = 1000, mcmc=50000, thin=100, verbose=TRUE, theta.constraints = list(V549=1, V443=-1)) The MCMCirt1d command seems to work fine, but when I try to