similar to: Parameter Estimation in R with Sums and Lagged Variables

There is a thread on this topic already: http://finzi.psych.upenn.edu/Rhelp10/2010-August/250934.html I'm rather mystified by a similar problem and wondering whether I've overlooked something obvious. I'm running with latest versions of R and all packages, and latest version of JAGS running under Windows 7. Here's the problem. I have some source code. It's given below -

Hi all-- We are planning an intervention study for adolescent alcohol use, and I am planning to use simulations based on a hurdle model (using the hurdle() function in package pscl) for sample size estimation. The simulation code and power code are below -- note that at the moment the "power" code is just returning the coefficients, as something isn't working quite right. The

Hi I am trying to use the deriv and eval functions to obtain the value of a function , say "xi-(alpha0+alpha1*gi)" , differentiated with respect to alpha0 and alpha1, in the following way # for gi = 0 > dU1dtheta <- deriv(~ xi-(alpha0+alpha1*gi), c("alpha0","alpha1")) > eval(dU1dtheta) (Intercept) -0.2547153 attr(,"gradient")

Hi R-friends, Attached is the SAS XPORT file that I have imported into R using following code library(foreign) mydata<-read.xport("C:\\ctf.xpt") print(mydata) I am trying to maximize logL in order to find Maximum Likelihood Estimate (MLE) of 5 parameters (alpha1, beta1, alpha2, beta2, p) using NLM function in R as follows. # Defining Log likelihood - In the function it is noted as

Dear all, Can any one tell me how can i perform Orthogonal Polynomial Regression parameter estimation in R? -------------------------------------------- Here is an "Orthogonal Polynomial" Regression problem collected from Draper, Smith(1981), page 269. Note that only value of alpha0 (intercept term) and signs of each estimate match with the result obtained from coef(orth.fit). What

I am trying to run WinBUGS 1.4 from the Ubuntu 6.10 Linux distribution. I am using the R2WinBUGS packages with the source file listed below. WinBUGS appears to run properly, but I get the following message after WinBUGS starts in WINE. Does anyone know what may be causing this error and what the correction may be? Thanks ERROR MESSAGE: fixme:ole:GetHGlobalFromILockBytes cbSize is 13824

Hi, I have generated a profile likelihood for a parameter (x) and am trying to get 95% confidence limits by calculating the two points where the log likelihood (LogL) is 2 units less than the maximum LogL. I would like to do this by linear interpolation and so I have been trying to use the function approxfun which allows me to get a function to calculate LogL for any value of x within

Hello R-list-members, I'm trying to model ARMA(0,2) & GARCH(1,1) process using the code below, but according to my textbook, the estimated parameters are wrong. The MA-parameters should be negative. (I've got the same problem using garchFit()). Can anyone tell me what I'm doing wrong? And how can I calculate the hessian matrix? Many thanks, Desislava Kavrakova Code:

I'm trying to build R 2.10.1 on a Sun Blade 1000 running Solaris 10 (03/05 release). I've installed iconv 1.13.1 and used: CPPFLAGS="-I /export/home/drkirkby/sage-4.3.3.alpha0/local/include" (which is where iconv is) LDFLAGS= -R/export/home/drkirkby/sage-4.3.3.alpha0/local/lib -L/export/home/drkirkby/sage-4.3.3.alpha0/local/lib The build of R fails as below. gcc

Hello everyone, I'm trying to estimate the parameters of the returns series attached using the GARCH code below, but I get the following error message: Error in solve.default(Hessian) : system is computationally singular: reciprocal condition number = 0 Error in diag(solve(Hessian)) : error in evaluating the argument 'x' in selecting a method for function 'diag' Can

Hi All: I had a basic question to ask. I am running R2WinBUGS so that I could automate the running of my model using 1000 simulated datasets. Below is the code I am using. The only problem I am having is the bugs output that comes out shows my parameters as nos with 1 decimal place after. I would want to have the parameters with 5 places after decimal. How would I specify that in my code for

Thanks to Gabor for setting me right. My code is as follows. I found it useful for learning optim(), and you might find it similarly useful. I will be most grateful if you can guide me on how to do this better. Should one be using optim() or stats4::mle? set.seed(101) # For replicability # Setup problem X <- cbind(1, runif(100)) theta.true <- c(2,3,1) y <- X

Dear R experts, We've been playing with the locfit package and are experiencing a problem I am hoping for some help on. We have a dataset of 13k points, one dimension of which is "judgment", either 0 or 1, and the other "score", an arbitrary scalar (in this case it's between .65 and .85). We use

Hello, I have a question about error handling. I run simulation studies and often the program stops with an error, for example during maximum likelihood. I would like the program not to stop but to continue and I would like to ask how the error handling can be set up for this (if it can). I tried to look through manuals etc but unfortunately did not get closer to the solution. Below is a

Hello- I'm new to R, coding and stats. (Oh no.) Anyway, I have about 12000 data points in a data.frame (dealing with dimensions and geological stage information for fossil protists) and have plotted them in a basic scatter plot. I also added a boxplot to overlay these points. Each worked fine independently, but when I attempt to superimpose them with add=true, I get a different scale for

Hello, I tried to fit a lognormal distribution by using optim. But sadly the output seems to be incorrect. Who can tell me where the "bug" is? test = rlnorm(100,5,3) logL = function(parm, x,...) -sum(log(dlnorm(x,parm,...))) start = list(meanlog=5, sdlog=3) optim(start,logL,x=test)$par Carsten. [[alternative HTML version deleted]]

It turns out that when I use GUI (file-change dir) to set the working directory, R will crash. If I use setwd() instead, the example runs well. Regards, On 4 April 2011 00:17, Wincent <ronggui.huang@gmail.com> wrote: > OK, I dig into the problem and found that Chinese character in the path > should be blamed. > Once the path rename to English only, it works. > > Regards,

* Ralf Hildebrandt <Ralf.Hildebrandt at charite.de>: > > It seems to loop in sha1_loop & hash_format_loop > > The problem occurs in both 2.3 and 2.2 (I just updated to 2.3 to check). I'm seeing the first occurence of that problem on the 10th of october! I was using (prior to the 10th) : 2.3.0~alpha0-1~auto+371 On the 10th I upgraded (16:04) to:

I've run into persistent problems with OpenBUGS crashing when using BRugs .53 and .71, and am hoping someone has suggestions. There is obviously something unusual going on in my environment, but I'm at a loss as to where to begin to try to solve it. In a nutshell, what happens is that, as soon as I call "modelCheck()" in BRugs, it gets an error or crashes ... but only some of

Hey, I'm trying to implement a GARCH model with Johnson-Su innovations in order to simulate returns of financial asset. The model should look like this: r_t = alpha + lambda*sqrt(h_t) + sqrt(h_t)*epsilon_t h_t = alpha0 + alpha1*epsilon_(t-1)^2 + beta1 * h_(t-1). Alpha refers to a risk-free return, lambda to the risk-premium. I've implemented it like this: #specification of the model