Re: g++/gcc : Floating point issue

[Neil Ferguson <nferguso at eso dot org>]

This is not a GCC issue.

The 'double' type has a finite precision. Your number is almost certainly
being approximated to the nearest representable value.

The only ways to deal with this are to:
(1) arrange your calculations so that finite precision is not an issue, or
(2) use a different data format.

If you're interested in option (2), GMP might meet your needs:

    http://www.swox.com/gmp/

Neil.

abuzer.salik@tcs.com wrote:
> Hi,
>
> I have an application which uses double values a lot. If I try to put say
> 401.74 in a double variable it is getting stored as 401.74000000000001
> which creates problem in the calculations down the line. ( I am checking
> these values using gdb debugger).
>
> So, I am wondering if there is a way by which I can store the correct
> values (i.e. 401.74) in the double.
>
> We are using g++ compiler on Linux box.
>
> Do we need to look for another compiler/hardware or current setup can
> handle this?
>
> Any suggestion/solution is highly appreciated.
>
> Regards,
> Abuzer Salik