From: Yamaha / XYZZ <scriven AT CS DOT ColoState DOT edu>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Problems with DJGPP V2.01 - atof() function
Date: Mon, 02 Dec 1996 12:25:59 -0700
Organization: XYZZ Software Co.
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Message-ID: <32A32D47.7DE1@CS.ColoState.edu>
References: <329e68a5 DOT 10316617 AT news DOT ua DOT pt>
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To: djgpp AT delorie DOT com
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afonso AT inesca DOT inesca DOT pt wrote:

>                 char string[]="1.13";
>                 int  result;
>                 ...
>                 result = (int)(atof(string)*100);
>                 ...
> 
>         I've got result = 112!!! not 113 as I wished, because
> the function atof() return is 1.29999... not 1.13 (and I only have
> an old i386).
>         I think that problem is a bug of DJGPP Library V2.xx.
>         Has someone noticed that problem and corrected it? If they
> have, please let me know about it.

Not a library bug.  It's probably due to truncation.  When you convert
floating point values to integer values, there is no rounding done. 
Instead, everything after the decimal point is dropped.  1.1299999 *
100.0 is 112.9999, and will always be 112 when converted to an integer
unless you purposely round up.


-- Yamaha / XYZZ
mailto:scriven AT CS DOT ColoState DOT edu          
mailto:scriven AT VIS DOT ColoState DOT edu
http://www.vis.colostate.edu/~scriven/