NaN and linear algebra

On 17/03/2005, at 10:00 PM, r-sig-mac-request@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