Subject: sign(exp(2009)) --> floating point overflow
From: reyssat
Date: Sat, 17 Oct 2009 21:53:56 +0200
Barton Willis a ?crit :
> I filed a bug report on sign(exp(2009)) --> floating point overflow
> (Sourceforge bug ID: 2880923). Since this bug causes several related
> bugs such as sqrt(4*exp(2009)) --> overflow, so I'm reporting it to
> the mailing list too:
>
> (%i13) sign(exp(2009));
> Maxima encountered a Lisp error:
> FLOATING-POINT-OVERFLOW detected performing EXP on (2009.0)
>
> (%i18) sqrt(4*exp(2009));
> Maxima encountered a Lisp error: FLOATING-POINT-OVERFLOW detected
> performing EXP on (2009.0)
>
> (%i22) realpart(sqrt(exp(2009)-1));
> Maxima encountered a Lisp error: FLOATING-POINT-OVERFLOW detected
> performing EXP on (2009.0)
>
> (%i14) build_info();
>
> Maxima version: 5.19post
> Maxima build date: 5:44 10/17/2009
> Host type: i686-pc-mingw32
> Lisp implementation type: Clozure Common Lisp
> Lisp implementation version: Version 1.4-dev (WindowsX8632)
>
> Barton
>
>
Just for info, I have no problem on my windows 5.17 version of maxima :
(%i2) sign(exp(2009));
(%o2) pos
(%i3) sqrt(4*exp(2009));
(%o3) 2*%e^(2009/2)
(%i4) realpart(sqrt(exp(2009)-1));
(%o4) sqrt(%e^2009-1)
(%i5) build_info();
Maxima version: 5.17.1
Maxima build date: 19:10 12/18/2008
host type: i686-pc-mingw32
lisp-implementation-type: GNU Common Lisp (GCL)
lisp-implementation-version: GCL 2.6.8
Eric Reyssat