search for: ghk

Dear R-community, not to re-invent the wheel I wonder if someone of you has ever written a function to compute the GHK smooth recursive simulator to estimate multivariate normal probabilities. See for instance page 194 of @BOOK{Greene97, author = {William H. Greene}, year = 1997, title = {Econometric Analysis}, edition = {3rd}, publisher = {Prentice-Hall}, address = {New Jersey 07458} } Thank you....

Hi, I am wondering if anybody has already written a GHK Simulator function for an ordered probit model in R? We have a system of three equations where the variables can take ordered categorial values. Thanks a million, Pensi

Dear R-List, to assess the model fit for 2PL-models, I tried to mimic the bootstrap-approach chosen in the GoF.rasch()-function. Not being a statistician, I was wondering whether the following simplification (omit the "chi-squared-expressed model fit-step") would be appropriate: GoF.ltm <- function(object, B = 50, ...){ liFits <- list() for(i in 1:B){ rndDat <-

I want to extract the last 3 letters of a string. So far, I've done this: > symbol = 'XYZ.VX" > substr(symbol,nchar(symbol)-2,nchar(symbol)) [1] ".VX" It works, but the code looks UGLY as hell. Am I missing something? Or is this the way it's supposed to be? Thanks, Sergio On 10/15/07, pintinho <diego at bpgomes.com> wrote: > > Hi everyone, >

Hola estimados miembros de la lista, Tengo una inquietud. Les cuento: tengo un conjunto de datos en un data.frame. Algunas de las variables que están en él son del tipo factor. Estos factores, naturalmente, tiene categorías: a veces demasiadas categorías y muchas de ellas con 1 individuo contemplando el data.frame más de 1 millón de individuos. Estas pequeñas cantidades creo que me están