[R-SIG-Mac] NaN and linear algebra

[Don MacQueen]

Same result here.
-Don

>  version
          _                       
platform powerpc-apple-darwin6.8.5
arch     powerpc                 
os       darwin6.8.5             
system   powerpc, darwin6.8.5    
status                           
major    2                       
minor    0.1                     
year     2004                    
month    11                      
day      15                      
language R                       


At 11:57 AM +0000 3/16/05, David Firth wrote:
>I don't know whether this is a bug, or a problem with the way I 
>built R 2.0.1 (under Mac OS 10.3 on a G5), or something else.  Can 
>anyone else confirm (or otherwise) that this happens in their R 
>2.0.1 on Mac OS X?
>
>  >  d<-matrix(NaN,3,3)
>>   d
>     [,1] [,2] [,3]
>[1,]  NaN  NaN  NaN
>[2,]  NaN  NaN  NaN
>[3,]  NaN  NaN  NaN
>>   solve(d)
>Error in solve.default(d) : Lapack routine dgesv: system is exactly singular
>>   chol(d)
>Error in chol(d) : the leading minor of order 1 is not positive definite
>>   det(d)
>[1] 0
>
>Doing the same thing on a Windows setup gave a different (and more 
>useful, I think) result
>
>>  d<-matrix(NaN,3,3)
>>  d
>     [,1] [,2] [,3]
>[1,]  NaN  NaN  NaN
>[2,]  NaN  NaN  NaN
>[3,]  NaN  NaN  NaN
>>  solve(d)
>     [,1] [,2] [,3]
>[1,]  NaN  NaN  NaN
>[2,]  NaN  NaN  NaN
>[3,]  NaN  NaN  NaN
>>  chol(d)
>     [,1] [,2] [,3]
>[1,]  NaN  NaN  NaN
>[2,]    0  NaN  NaN
>[3,]    0    0  NaN
>>  det(d)
>[1] NaN
>
>Any thoughts?
>David
>
>Professor David Firth
>Dept of Statistics
>University of Warwick
>Coventry CV4 7AL
>United Kingdom
>
>Voice: +44 (0)247 657 2581
>Fax:   +44 (0)247 652 4532
>Web:   http://www.warwick.ac.uk/go/dfirth
>
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-- 
--------------------------------------
Don MacQueen
Environmental Protection Department
Lawrence Livermore National Laboratory
Livermore, CA, USA