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Dear R users, we are trying to do some parallel computing using library(snow). In particular we have a cluster with 3 nodes >cl <- makeCluster(3, type = "MPI") 3 slaves are spawned successfully. 0 failed. and we want to compute the function op_mat (see below) first with the master and then with the cluster using system.time for checking the computational performance.

Dear R-Users, I have a model with a latent variable for a spatio-temporal process. I would like to use EM algorithm to estimate the parameters. Does anybody know how to implement the algorithm in R? Thank you very much in advance, Michela

Dear R-users, we are using library(snow) for computation on a linux cluster with RMPI. We have a problem with clusterEvalQ: after launching clusterEvalQ it seems loading the required library on each node but if we type a function belonging to the loaded package R doesn't find it. > library(snow) # making cluster with 3 nodes > cl <- makeCluster(3, type = "MPI") Loading

Dear R-users, I have a little problem that I can't solve by myself. I have a data frame with 2 factors and 8 observations (see the following code): y <- c(1,1,1,2,2,3,3,3) y <- factor(y) levels(y) <- c("a","b","c") x <- c(1,2,3,1,2,1,2,3) x <- factor(x) levels(x) <- c("x","y","z") X <-

Dear R user, I'm trying to find a solution for optimizing my code. I have to run a 50.000 iteration long simulation and it is absolutely necessary to have an optimized code. I have to do this operation *sum_t ( t(X_t) %*% A %*% X_t )* where X_t is a (d*k) matrix which changes in time and A is a constant in time (d*d) matrix. I have put all my X_t in a three dimensional array X of dimension

CRAN (and crantastic) updates this week New packages ------------ * apcluster (1.0.1) Ulrich Bodenhofer http://crantastic.org/packages/apcluster The apcluster package implements Frey's and Dueck's Affinity Propagation clustering in R. The algorithms are analogous to the Matlab code published by Frey and Dueck. * BioPhysConnectoR (1.6-1) Franziska Hoffgaard

Dear R-Users, I'm using SSPIR package for a spatio-temporal application. Is it possible to modify the structure of the involved matrixes (Fmat, Gmat, Vmat,Wmat)? I want to create a model like this #y(t)=k*theta(t)+epsilon(t) #theta(t)=h*theta(t-1)+eta(t) #epsilon(t) N(0,V) V=sigma2*I #eta(t) N(0,W) W=sigma2_eta where the state variable theta has dimension 1(p=1) and at

Dear R-Users, we are using a linux-cluster with RMPI and the snow package. We would like to do a double boostrap. We have a general function that implements the first boostrap (the outer) and we are wondering if we can include another bootstrap (the inner) in the same general function including another clusterApplyLB. For example: general function = function(...) { clusterApplyLB(cl,

Hi all, I'm using RScalapack library for parallelizing some heavy matrix operations required by MCMC methods for spatio-temporal models. The package reference manuals (dated 2005) states that the library needs LamMPI to work but we have a Linux Cluster with OpenMPI. We have found (http://cvs.fedoraproject.org/viewvc/devel/R-RScaLAPACK/) a patch for OpenMPI but we are wondering if in the