similar to: Discrete trait Ornstein–Uhlenbeck in R?

Dear friends i am trying to fit an Ornstein-Uhlenbeck process by MAXIMUM LIKELYHOOD method. i found these formulas on http://www.sitmo.com/article/calibrating-the-ornstein-uhlenbeck-model/ this is the mean-reverting process http://r.789695.n4.nabble.com/file/n4637271/process.txt process.txt and this is the script that i am using....... ouFit.ML=function(spread) { n=length(spread)

hello everyone, i'm trying to simulate a 2-parameter integrated ornstein-uhlenbeck (IOU) process, but i'm not sure exactly where to start (which package, which function). the motivation is the paper by taylor et. al. (JASA 1994) "a stochastic model for the analysis of longitudinal aids data." the model they suggest consists of a combination of fixed and random effects, a

dear useRs, i'm working with a mean reverting model of the following specification: y = mu + beta(x - mu) + errorterm, where mu is a constant currently I estimate just y = x (with lm()) to get beta and then calculate mu = estimated intercept / (1-beta). but I'd like to estimate mu and beta together in one regression-step and also get the test-statistics (including parameter

Dear all, I wanted to let you know about four phylogenetic comparative methods (PCM) packages that have become available on (3 on CRAN and 1 on GitHub) recently that hopefully will be interesting to somebody. Three of them go significantly beyond the Brownian motion (BM) and Ornstein-Uhlenbeck (OU) processes. 1) There is a new version of mvSLOUCH available. The most important change is that the

Dear all, I wanted to let you know about four phylogenetic comparative methods (PCM) packages that have become available on (3 on CRAN and 1 on GitHub) recently that hopefully will be interesting to somebody. Three of them go significantly beyond the Brownian motion (BM) and Ornstein-Uhlenbeck (OU) processes. 1) There is a new version of mvSLOUCH available. The most important change is that the

Dear all, I have just uploaded to CRAN the version 1.6 of the package 'adehabitat'. Significant changes are listed below: * The package has been reorganized into four parts (see ?adehabitat-package for a description): (i) management of raster maps, (ii) habitat selection / ecological niche analysis, (iii) home range analysis, and (iv) analysis of animals trajects. The package contains

Dear all, I have just uploaded to CRAN the version 1.6 of the package 'adehabitat'. Significant changes are listed below: * The package has been reorganized into four parts (see ?adehabitat-package for a description): (i) management of raster maps, (ii) habitat selection / ecological niche analysis, (iii) home range analysis, and (iv) analysis of animals trajects. The package contains

Hello. I try to compute a "White-corrected" ANOVA. Therefore I use the command "Anova" implemented in the car()-package): Anova(modelname, white.adjust="hc3") and receive the error message: "Fehler in SS[i] <- SS.term(names[i]) : nichts zu ersetzen" (German) "Error in SS[i] <- SS.term(names[i]) : nothing to replace" (probably being the

Hi, I am looking for any procedure in R to fit "Latent variables models" in particular "Latent trait models (i.e. for binary data)". could anyone help me? Many thanks , Dr Abderrahim Oulhaj Oxford University Department of Pharmacology Mansfield Road Oxford OX1 3QT Tel: +44 1865 224098 Fax: +44 1865 224099 Email: abderrahim.oulhaj@pharmacology.oxford.ac.uk

Ein eingebundener Text mit undefiniertem Zeichensatz wurde abgetrennt. Name: nicht verf?gbar URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20130611/09dcb017/attachment.pl>

Dear R-users, I'd like to announce the release of my new package "ltm" (available from CRAN), for fitting Latent Trait Models (including the Rasch model) under the Item Response Theory approach. The latent trait model is the analogous of the factor analysis model for Bernoulli response data. "ltm" fits the linear one- and two-factor models but also allows for

Dear R-users, I'd like to announce the release of my new package "ltm" (available from CRAN), for fitting Latent Trait Models (including the Rasch model) under the Item Response Theory approach. The latent trait model is the analogous of the factor analysis model for Bernoulli response data. "ltm" fits the linear one- and two-factor models but also allows for

Hello, I got an error message saying Error in lognet(x, is.sparse, ix, jx, y, weights, offset, alpha, nobs, : NA/NaN/Inf in foreign function call (arg 5) when I try to analysis a binary trait using glmnet(R) by running the following code library(glmnet) Xori <- read.table("c:\\SNP.txt", sep='\t'); Yori <- read.table("c:\\Trait.txt", sep=',');

Hello all, could anyone explain the exact meaning of parameter nproc? Why different values of nproc give so different critical values, i.e. meanL2BB$computeCritval(0.05,nproc=3) [1] 0.9984853 meanL2BB$computeCritval(0.05,nproc=1) [1] 0.4594827 The strucchange-package description gives "integer specifying for which number of processes Brownian motions should be simulated" - do I need

I would like to plot multiple random walks onto the same graph. My p variable dictates how may random walks there will be. par(mfrow=c(1,1)) p <- 100 N <- 1000 S0 <- 10 mu <- 0.03 sigma <- 0.2 nu <- mu-sigma^2/2 x <- matrix(rep(0,(N+1)*p),nrow=(N+1)) y <- matrix(rep(0,(N+1)*p),nrow=(N+1)) t<- (c(0:N))/N for (j in 1:p) { z <- rnorm(N,0,1) x[1,j] <- 0 y[1,j]

Hi, I have been using maxLik to do some MLE of Geometric Brownian Motion Process and everything has been going fine, but know I have tried to do it with jumps. I have create a vector of jumps and then added this into my log-likelihood equation, know I am getting a message: NA in the initial gradient My codes is hear # n<-length(combinedlr) j<-c(1,2,3,4,5,6,7,8,9,10)

Hi, I'm part of an engineering team doing research on persistent memory support and we have stumbled upon an interesting problem. The issue is, we would like to be able to use the standard library containers in a persistent memory context (think NVDIMM-N). What I mean is that you allocate a container from said memory, use it like you normally would. After the application terminates, expectedly

Dear R Helpers, I have searched for any R package or code for simulating multivariate fractional Brownian motion (mFBM) or multivariate fractional Gaussian noise (mFGN) when a covariance matrix are given. Unfortunately, I could not find such a package or code. Can you suggest any solution for multivariate FBM and FGN simulation? Thank you for your help. Best Regards, Ryan ----- Wonsang You

Hi: I was wondering whether I can find some help for computer simulation of stochastic processes (e.g. Brownian motion), for pedagogicl/instructional purposes. Any help would be appreciated. thanks, Ravi.

Hi, I'm writing a short course tutorial to Browninan Motion/ Langevin Equation. At the end of the theory section I wanted to add a short GNU R example, so the students can play a little around. I already looked in the MASS book (by Venables and Ripley) but I couldn't find any Brownian Motion/ Langevin Equation package. Are there any good packages or tutorials available which cover R and