Subject: Maxima gives incorrect results with ceiling
From: Stavros Macrakis
Date: Fri, 7 Dec 2007 16:10:35 -0500
On Dec 7, 2007 3:30 PM, Daniel Lakeland <dlakelan at street-artists.org> wrote:
> A proposal for the method of doing ceiling and floor with exact
> results:
>
> ...first bfloat the input to whatever the current precision is.
I don't see how any method starting like this can possibly work;
cancellation may make the result much smaller than any intermediate results.
> Then extract the base 2 exponent of the bfloat, and if the exponent is
> larger than the current precision, set the current digits to the
> appropriate precision necessary to ensure exact integer
> representation.