[R-SIG-Mac] NaN and linear algebra

[Bill Northcott]

On 17/03/2005, at 10:00 PM, r-sig-mac-request at stat.math.ethz.ch 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
>
These are features/bugs of Apple's LAPACK library.  You would do better 
to ask Apple support or float the question on the scitech list.  They 
have nothing to do with R code.

Bill Northcott