[Csdp] Differences between versions 5 and 6

Brian Borchers borchers at nmt.edu
Thu Feb 28 16:06:16 EST 2008


>Notice also that the numerical results are slightly different (using 
>the same single processor).

That's not surprising.  When code is compiled by different compilers
(or with the same compiler using different optimization options) the
floating point arithmetic operations aren't always performed in the
same order, so the arithmetic can round off differently.  These
differences are compounded by if/then branches in the code so that you
can get substantially different answers in the end.

Things get even more complicated when you introduce different
implementations of BLAS/LAPACK that may be using substantially
different algorithms.


More information about the Csdp mailing list