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

[Stefano Iacus]

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 Venerd́, 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 --
>
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