Dear R users, I try to compute this summation,
http://www.nabble.com/file/p25054272/dd.jpg where f(y|x) = Negative Binomial(y, mu=exp(x' beta), size=1/alp) http://www.nabble.com/file/p25054272/aa.jpg http://www.nabble.com/file/p25054272/cc.jpg In fact, I tried to use "do.call" function to compute each u(y,x) before the summation, but I got an error, "Error in X[i, ] * t(beta) : non-conformable arrays". Here is my code. #---------------------------------------------------------------------------------- # data ------------------------------------------------------------ yy <- c(2,2,10,3,6,7,9,9,14,6) x1 <- c(0,0,0,0,0,1,0,0,0,0) x2 <- c(1,1,0,1,0,0,0,0,0,0) x3 <- c(0,0,1,0,0,0,0,0,0,0) x4 <- c(0,0,0,0,0,0,0,0,0,0) x5 <- c(0,0,0,0,0,0,0,0,0,1) x6 <- c(0,0,0,0,1,0,0,0,0,0) n <- length(yy) x <- cbind(x1,x2,x3,x4,x5,x6) X <- cbind(1,x) p <- 7 #### p:#beta library(numDeriv) # u function ------------------------------------------------------- obj <- function(theta,i,j) { beta <- theta[1:p] alp <- theta[p+1] log(dnbinom(yy[j], mu=exp(rowSums(X[i,] * t(beta))), size=1/alp)) } list <- expand.grid(j=seq(1,n),i=seq(1,n)) func <- function(i,j) { grad(func=obj,i=i,j=j, x=c(1.50, 0.02, 0.09, 0.22, 0.17, -0.08, -0.13, 0.04)) } do.call( func, list ) #------------------------------------------------------------------------------------ Any suggestion will be greatly appreciated. Regards, Kathryn Lord -- View this message in context: http://www.nabble.com/how-to-compute-this-summation...-tp25054272p25054272.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
