Long-float variant giving more precision to numerical computations.

Douglas Crosher wrote:
>
> The slatec Fortran source comments suggests it is precise enough for
> double-double float.  The code can be re-translated, maintaining the
> constant precision, using the following hack patch.
>
> F2cl hack patch to target Fortran double precision to long-float or
> double-double-float:
> http://www.scieneer.com/files/f2cl-patch1.txt.gz
>
> Add the following compiler-options in slatec.system and rebuild:
>  :double-precision-format kernel:double-double-float
>  :float-format kernel:double-double-float
>
>
Finally got around to applying this patch to f2cl.  I tried it with 
quadpack, and the translation looks good.  Unfortunately, the 
translation won't work because the f2cl-lib functions need to be changed 
to support double-double-float.  A quick hack of f2cl-lib gives 
something that runs, but one simple test of quadpack dqag produces 
results that aren't very accurate.

More work needed, I guess.

Ray