Re: NaN problem

[John W. Eaton]

On  7-Feb-2000, address@hidden <address@hidden> wrote:

| > What do the vendor-specific versions of the BLAS do for this code?
| > What does ATLAS do?
| 
| ATLAS 3.0beta handles it correctly:
| 
| octave:1> [0;0]*[ inf nan ]
| ans =
| 
|            NaN           NaN
|            NaN           NaN
| 
| octave:2> [ inf; nan ]*[0 0]
| ans =
| 
|            NaN           NaN
|            NaN           NaN

That's nice to know.

| I don't know about the vendor BLAS libraries.

They are probably just serving up wrong answers fast.  :-)

On a Digital Unix system that I have access to, the dxml library
doesn't even seem to have been compiled to handle IEEE Inf and NaN,
though I built Octave so that it should:

  octave:3> [ inf; nan ]*[0 0]
  ans =

    0  0
    0  0

  octave:4> [0;0]*[ inf nan ]
  error: floating point exception -- trying to return to prompt

  octave:4> Inf * 0
  ans = NaN


Thanks,

jwe



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