Re: [Gcl-devel] Re: [Maxima] float to bfloat

[Richard Fateman]

test integer-decode-float  on NaN, Infinity, etc.
before you decide your program is correct.   I think that
such non-numbers should be "bigfloated" into symbols / gensyms
with appropriate properties.
e.g. NaN - NaN  = NaN     (not 0).
Complicates matters!
RJF


Camm Maguire wrote:

> Greetings!
>
> Raymond Toy <address@hidden> writes:
>
>  
>
> > > > > > > "Camm" == Camm Maguire <address@hidden> writes:
> > > > > > >              
> >    Camm> I don't think this is the case:
> >
> > My apologies.  I didn't test it.  I used to have problems with gcl's
> > float reader/printer, but I guess you've fixed those.  Nice!
> >
> >    Camm> OK, will consider after Stavros gets a chance to look into things next
> >    Camm> week.  Thanks again to all!
> >
> > FWIW, I ran your test function on cmucl.  It passes the test case
> > (test-f 1d0 10).  Also, there were a couple of minor bugs.  float
> > should take the 2nd arg, otherwise it converts to single-float be
> > default.  This was messing up cmucl. :-)
> >
> >    
>
> Thanks.  Just a clarification here, this test also passes with GCL's
> current rationalize, just not (yet) with the proposed improved one.
>
> Take care,
>
>  
>
> > (defun test-f (x i)
> >  (multiple-value-bind
> >      (q r s)
> >      (integer-decode-float x)
> >    (format t "~S~%" x)
> >    (and (eql x (float (* q (expt 2 r)) x))
> >         (eql (float (rationalize x) x) x)
> >         (if (> i 0)
> >             (test-f (float (* (+ q 1) (expt 2 r)) x) (- i 1))
> >             t))))
> >
> > Ray
> >
> >
> >
> >
> >    
>
>