APM: Perl zero not being zero, but 7e-12

Comrade Burnout brian_clarkson at yahoo.com
Mon Sep 12 22:54:51 PDT 2005


i got bit by that once ... and i resorted to sprintf() ... 

the floating point arithmetic is the root cause, i think.

--- Wayne Walker <wwalker at bybent.com> wrote:

> Number::Tolerant seems to be one way, but YECH.
> 
> On Mon, Sep 12, 2005 at 10:46:23AM -0500, David Bluestein II wrote:
> > Okay, I've seen this before and have a question how to avoid it.
> > 
> > I take two variables:
> > 
> > $a= 38071.63;
> > $b = $i + $j; # Where $i + $j => 38071.63
> > 
> > print "$a : $b"; # results in 38071.63 : 38071.63
> > 
> > Yet if I do:
> > 
> > if ($a == $b) {
> > print "Equal";
> > } else {
> > print "Not equal";
> > }
> > 
> > I get a "Not equal".
> > 
> > If I subtract ($b-$a) the result is 7.27595761418343e-12. How do I get
> 
> > Perl to ignore this "noise" which comes from someplace?
> > 
> > David
> > 
> >
> -----------------------------------------------------------------------
> > David H. Bluestein II
> > President & Lead Developer         dbii at interaction.net
> > ii, inc.                                                  
> > http://www.interaction.net
> >      -- Specializing in Interactive, Database Driven Websites --
> > 
> > _______________________________________________
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> 
> -- 
> 
> Wayne Walker
> 
> wwalker at bybent.com                    Do you use Linux?!
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> 


i'm trying to get away from this mail account as much as possible.  it's become a spamtrap.

please reply to , or update your address books to, geektron at comradeburnout.com


		
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