From becker at kfs.oeaw.ac.at  Mon Mar  7 09:35:39 2005
From: becker at kfs.oeaw.ac.at (becker@kfs.oeaw.ac.at)
Date: Mon Mar  7 09:35:47 2005
Subject: [Rd] R crashes using the em function of package mclust (PR#7719)
Message-ID: <20050307083539.1F66DB273@slim.kubism.ku.dk>

Hi,

I got the same problem like
http://tolstoy.newcastle.edu.au/R/devel/04/11/1204.html

R crashes when I use the em function from the mclust package on 
univariate data and on a special case on bivariate data (when the matrix 
is not provided as written in the manual).
It seems as if the problem is the format of the data to be analyzed.

Operating System: Windows XP (SP2)
R version: R-2.0.1

The following example causes a crash of R:

# univariate example
require(mclust)
X <- c(rnorm(100, mean=1), rnorm(100, mean=5))
# I also tried: X <- as.matrix(c(rnorm(100, mean=1), rnorm(100, mean=5)))
Xmap <- cbind(c(rep(1, 100), rep(0, 100)), c(rep(0, 100), rep(1, 100)))
Xm <- mstep(modelName="V", data=X, z=Xmap)
# CRASH:
em(modelName=Xm$modelName, data=X, mu=Xm$mu, sigmasq=Xm$sigmasq, pro=Xm$pro)

For bivariate data the following example works:

# bivariate example
require(mclust)
Y <- as.matrix(cbind(c(rnorm(100, mean=1), rnorm(100, mean=5)), 
c(rnorm(100, mean=1), rnorm(100, mean=5))))
Ymap <- cbind(c(rep(1, 100), rep(0, 100)), c(rep(0, 100), rep(1, 100)))
Ym <- mstep(modelName="EEE", data=Y, z=Ymap)
# NO CRASH:
em(modelName=Ym$modelName, data=Y, mu=Ym$mu, sigmasq=Ym$Sigma, pro=Ym$pro)

But when the variables are not columns (as written in the mclust manual) 
but rows, R crashes again:

# CRASH:
em(modelName=Ym$modelName, data=t(Y), mu=Ym$mu, sigmasq=Ym$Sigma, 
pro=Ym$pro)

Perhaps this is a hint to the origin of the problem.
I could not use the em function for univariate data successfully yet.
Perhaps anyone can provide a working example for univariate data?

Thanks in advance.


[Rd] R crashes using the em function of package mclust (PR#7719)
becker@kfs.oeaw.ac.at