From Thomas Vogels <tov@ece.cmu.edu>  Thu Jun 15 18:57:55 2000
From: Thomas Vogels <tov@ece.cmu.edu> (Thomas J Vogels)
Date: 15 Jun 2000 13:57:55 -0400
Subject: [Rd] eigen broken on AIX with R-devel? (PR#537)
In-Reply-To: tov@ece.cmu.edu's message of "Mon, 8 May 2000 18:00:52 +0200 (MET DST)"
References: <200005081600.SAA10511@pubhealth.ku.dk>
Message-ID: <87vgzax1wc.fsf@bavaria.ece.cmu.edu>


Hi, I ran the test again with the newly released version of R (1.1) and I
now get the correct eigen values.  ("make check" succeeds.)

The scary part is that I think that I also used gcc+f77 last time and
the libs weren't changed.  Maybe the scary part is that I think...

So the comments that this is compiler specific probably hold.

Thanks,
  -tom


tov@ece.cmu.edu writes:

> Hi,  I get the wrong eigen values on an AIX machine with R-devel of 5/3/00.
> 
> Here are the results:
> 
> R> m <- matrix (c(6.8, 2.4, 2.4, 8.2), nrow=2)
> R> m
>      [,1] [,2]
> [1,]  6.8  2.4
> [2,]  2.4  8.2
> R> eigen(m)
> $values
> [1] 19.281403  6.337993
> 
> $vectors
>           [,1]       [,2]
> [1,] 0.1918866  0.9967987
> [2,] 0.9967987 -0.1918866
> 
> 
> And for comparison, here is what I get on a Sun (with r-stable):

(same results now on AIX 4.3 with R 1.1.0 

> R> m <- matrix (c(6.8, 2.4, 2.4, 8.2), nrow=2)
> R> eigen (m)
> $values
> [1] 10  5
> 
> $vectors
>      [,1] [,2]
> [1,]  0.6  0.8
> [2,]  0.8 -0.6

-- 
mailto:tov@ece.cmu.edu (Tom Vogels)   Tel: (412) 268-6638   FAX: -3204
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._


[Rd] eigen broken on AIX with R-devel? (PR#537)
Thomas J Vogels