st: Re: strange behavior using round function

["Michael Blasnik" <michael.blasnik@verizon.net>]

Apparently 80.54 can not be held exactly in binary double precision. 
Try -search precision- and follow some of the links.   If you really just 
want to display the result, use the formating available with display:

displ %6.2f  `t2_y'

Otherwise, you may want to read some of the related faqs.

Michael Blasnik
michael.blasnik@verizon.net

----- Original Message ----- 
From: "Nicola Tommasi" <nicola@cide.univr.it>
To: <statalist@hsphsun2.harvard.edu>
Sent: Tuesday, September 12, 2006 12:08 PM
Subject: st: strange behavior using round function



> hi all,
>
> I would appreciate if someone could help me understand why the ROUND 
> function behaves so differently when calculating t1_y and t2_y
> The result for t2_y should be 80.54
> Below follows the code.
>
> Thanks
>
> Sincerely,
>
> Nicola Tommasi
>
>
>
> . matrix list mati;
>
> mati[2,2]
>       c1    c2
> r1   818  1535
> r2   248   371
>
> . di "`tot1'";
> 1066
>
> . di "`tot2'";
> 1906
>
> . local t1_y = round(mati[1,1]/`tot1'*100, 0.01);
>
> . local t2_y = round(mati[1,2]/`tot2'*100, 0.01);
>
> . di "`t1_y'";
> 76.74
>
> . di "`t2_y'";
> 80.54000000000001
>
>
>
>
>
> ______________________________________________________________
>         dott. Nicola Tommasi
>         Centro Interdipartimentale di Documentazione Economica (C.I.D.E)
>         University of Verona
>         via dell'Artigliere, 19
>         37129 Verona (Italy)
>         tel.: +39-045-8028048
>         fax.: +39-045-8028047
> _______________________________________________________________________
>
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