optimized linear algebra library on Lenny
On Wed, May 28, 2008 at 02:14:03PM +0000, Dirk Eddelbuettel wrote:
On Wed, May 28, 2008 at 10:52:45AM -0300, tyler wrote:
I'd like to install the optimized libraries on my Thinkpad with an Intel Core Solo chip, which apparently supports the following instruction sets: MMX, SSE, SSE2, SSE3 instruction sets, XD-Bit. Is it as simple as: apt-get install libatlas3gf-sse2 And is there anything else that needs doing to tell R to use the new libraries?
No, everything else is automatic. See the (Debian-specific) README
below /usr/share/doc/libatlas*/
It's always instructive to run a test such as (taken from README.Atlas
below /usr/share/doc/r-base-core/ -- and I need to update package
names therein)
$ R --vanilla -q
> mm <- matrix(rnorm(10^6), ncol = 10^3)
> system.time(crossprod(mm))
[1] 28.28 0.08 33.54 0.00 0.00
>
Done. The results are impressive: Before: -> R --vanilla -q
mm <- matrix(rnorm(4*10^6), ncol = 10^3) system.time(crossprod(mm))
user system elapsed 12.836 0.012 13.327
After: -> R --vanilla -q
mm <- matrix(rnorm(4*10^6), ncol = 10^3) system.time(crossprod(mm))
user system elapsed 3.236 0.028 3.268
Thanks! Tyler
Philosophy of science is about as useful to scientists as ornithology is to birds.
--Richard Feynman