Re: g++/gcc : Floating point issue

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abuzer.salik@xxxxxxx wrote:

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.

No.

Only dyadic rationals (a rational number of the form a/(2^b) where a is an integer and b is a natural number) have a finite binary expansion.

  40174/100 = 200087/50    (and 50 is not 2^b for a natural number b)

See the links:
http://en.wikipedia.org/wiki/Binary_numeral_system#Representing_real_numbers
http://en.wikipedia.org/wiki/Dyadic_fraction


Do we need to look for another compiler/hardware or current setup can
handle this?

You can use an arbitrary precision numeric library, for ex. GMP
 http://www.swox.com/gmp/

Regars,
Luca.



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