# [R-SIG-Mac] Lion 10.7.1. Bug with Eigen. 64 bit.

Anirban Mukherjee anirbanm at smu.edu.sg
Sat Sep 3 14:34:03 CEST 2011

```Hi all,

I upgraded the OS to Mac OS Lion (10.7.1). Using a Mac Pro, dual
hexacore processors. In R (64 bit), the following computes very
quickly.

# --- CODE ---
require(Matrix)        # Optimized matrix operations
require(SuppDists)    # Optimized random number generators
Rnorm <- rziggurat    # The fast normal number generator

a <- array(Rnorm(500*500), dim = c(500, 500))       ###NOTE:
DIMENSIONS ARE 500 ###

eigen(a, symmetric=FALSE, only.values=TRUE)\$Value
# --- CODE ---

In R (64 bit), the following leads to a spinning wheel. I left it for
a few minutes but R remained non-responsive. Checked on both Rterm and
Rgui. Only change is a slight change in dimensions from 500 to 501.

# --- CODE ---
require(Matrix)        # Optimized matrix operations
require(SuppDists)    # Optimized random number generators
Rnorm <- rziggurat    # The fast normal number generator

a <- array(Rnorm(501*501), dim = c(501, 501))      ###NOTE: DIMENSIONS
ARE 501 ###

eigen(a, symmetric=FALSE, only.values=TRUE)\$Value
# --- CODE ---

Using R (32 bit), both snippets compute very quickly.

Best, Anirban

--
For Rgui 64 bit:

> R.Version()
\$platform
[1] "x86_64-apple-darwin9.8.0"

\$arch
[1] "x86_64"

\$os
[1] "darwin9.8.0"

\$system
[1] "x86_64, darwin9.8.0"

\$status
[1] "Patched"

\$major
[1] "2"

\$minor
[1] "13.1"

\$year
[1] "2011"

\$month
[1] "09"

\$day
[1] "02"

\$`svn rev`
[1] "56906"

\$language
[1] "R"

\$version.string
[1] "R version 2.13.1 Patched (2011-09-02 r56906)"

> sessionInfo()
R version 2.13.1 Patched (2011-09-02 r56906)
Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)

locale:
[1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] SuppDists_1.1-8    Matrix_0.9996875-3 lattice_0.19-33

loaded via a namespace (and not attached):
[1] grid_2.13.1

----
For Rgui 32 bit:

> R.Version()
\$platform
[1] "i386-apple-darwin9.8.0"

\$arch
[1] "i386"

\$os
[1] "darwin9.8.0"

\$system
[1] "i386, darwin9.8.0"

\$status
[1] "Patched"

\$major
[1] "2"

\$minor
[1] "13.1"

\$year
[1] "2011"

\$month
[1] "09"

\$day
[1] "02"

\$`svn rev`
[1] "56906"

\$language
[1] "R"

\$version.string
[1] "R version 2.13.1 Patched (2011-09-02 r56906)"

> sessionInfo()
R version 2.13.1 Patched (2011-09-02 r56906)
Platform: i386-apple-darwin9.8.0/i386 (32-bit)

locale:
[1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] SuppDists_1.1-8    Matrix_0.9996875-3 lattice_0.19-33

loaded via a namespace (and not attached):
[1] grid_2.13.1

```