Subject: How to deal with r^(bfloat(2/3))/r^(2.0/3)
From: Robert Dodier
Date: Thu, 13 Dec 2007 08:56:29 -0700
On 12/13/07, zycentre <zycentre-sub at yahoo.com.cn> wrote:
> If I quit maxima first, and restart, the result is:
> (%i1) bfloat(2/3)-2.0/3;
> (%o1) 4.163336342344337b-17
>
> I still want this small value to be vanished, as it will appear in an index.
Perhaps you mean exponent? As shown here ...
> When the result have one term like:
> r^4.163336342344337b-17
> looks not good.
What is the expression for which this is the result?
A general strategy: work with symbolic expressions,
then convert to float only at the end (or as late as possible).
> So, how to set in maxima, such as: if INDEX < 1.b-16, set INDEX =0 ?
> How to translate it into maxima language?
I don't quite understand what's going on here, but I suspect you
don't really need to do that.
best
Robert Dodier