From dweeks at watson.hgen.pitt.edu  Wed Mar  5 16:09:48 2003
From: dweeks at watson.hgen.pitt.edu (Daniel E. Weeks)
Date: Wed Mar  5 22:10:13 2003
Subject: [Rd] eigen() error: R Version 1.6.1 on Mac OS X (PR#2550)
In-Reply-To: <81E449CB-4064-11D7-8936-003065CC4CB8@mclink.it>
Message-ID: <BA8BD1CC.4DDA%dweeks@watson.hgen.pitt.edu>

Dear Stefano,

Yes, I have updated to R Version 1.6.2  (2003-01-10), running it in a
Terminal window under Darwin Kernel Version 6.4.

And, while La.eigen() appears to work fine, I still have the same problem
with eigen():

> x
     X1    X2    X3    X4    X5
1 3.240 2.592 2.592 2.592 2.592
2 2.592 3.240 2.592 2.592 2.592
3 2.592 2.592 3.240 2.592 2.592
4 2.592 2.592 2.592 3.240 2.592
5 2.592 2.592 2.592 2.592 3.240
> La.eigen(x)$values
[1] 13.608  0.648  0.648  0.648  0.648
> eigen(x)$values
[1] 13.123930  0.648000  0.648000  0.648000 -1.732930

I was hoping that updating to Version 1.6.2 would make my bug go away.

But if you can not reproduce this bug, then what is it about my system that
is different from yours?

Thank you,
  -- Dan --

On 2/14/03 4:37 PM, Stefano Iacus at jago@mclink.it wrote:

> Under Darwin R 1.6.2 and R-1.6.1 I get
> 
>> sg
>      [,1]  [,2]  [,3]  [,4]  [,5]
> [1,] 3.240 2.592 2.592 2.592 2.592
> [2,] 2.592 3.240 2.592 2.592 2.592
> [3,] 2.592 2.592 3.240 2.592 2.592
> [4,] 2.592 2.592 2.592 3.240 2.592
> [5,] 2.592 2.592 2.592 2.592 3.240
>> eigen(sg)$values
> [1] 13.608  0.648  0.648  0.648  0.648
> 
> as well as under Carbon R 1.6.1 and 1.6.2
> 
> I cannot reproduce your behaviour.
> 
> stefano
> 
> 
> 
> 
> On Venerd?, feb 14, 2003, at 21:37 Europe/Rome,
> dweeks@watson.hgen.pitt.edu wrote:
> 
>> Consider this matrix:
>> 
>>> sg
>>      X1    X2    X3    X4    X5
>> 1 3.240 2.592 2.592 2.592 2.592
>> 2 2.592 3.240 2.592 2.592 2.592
>> 3 2.592 2.592 3.240 2.592 2.592
>> 4 2.592 2.592 2.592 3.240 2.592
>> 5 2.592 2.592 2.592 2.592 3.240
>> 
>> If I compute the eigenvalues of the 'sg' matrix using R Version 1.5.0
>> (2002-04-29) under Linux (or using Version 1.4.0  (2001-12-19) under
>> Solaris), I obtain:
>> 
>>> eigen(sg)
>> $values
>> [1] 13.608  0.648  0.648  0.648  0.648
>> 
>> I also obtain the same eigenvalues under R Version 1.5.1  (2002-06-17)
>> under
>> Mac OS X 10.2.3.
>> 
>> However, if I compute the eigenvalues of the 'sg' matrix using R
>> Version
>> 1.6.1  (2002-11-01) under Mac OS X 10.2.3, I obtain a different answer:
>> 
>>> eigen(sg)
>> $values
>> [1] 13.123930  0.648000  0.648000  0.648000 -1.732930
>>> det(sg)
>> [1] 2.399354
>>> det(sg,method="eigenvalues")
>> [1] -7.312317
>> 
>> 
>> Thanks,
>>  -- Dan --
>> 
>> ______________________________________________
>> R-devel@stat.math.ethz.ch mailing list
>> http://www.stat.math.ethz.ch/mailman/listinfo/r-devel
>> 
> 
>


[Rd] eigen() error: R Version 1.6.1 on Mac OS X (PR#2550)
Daniel E. Weeks