c++ floating point precision loss: 3015/0.00025298219406977296

Question

The problem.

Microsoft Visual C++ 2005 compiler, 32bit windows xp sp3, amd 64 x2 cpu.

Code:

double a = 3015.0; 
double b = 0.00025298219406977296         


        

Answer 1

I'd guess you're printing out the number without specifying a precision. Try this:

#include 
#include 

int main() { 
    double a = 3015.0; 
    double b = 0.00025298219406977296;
    double f = a/b;

    std::cout << std::fixed << std::setprecision(15) << f << std::endl;
    return 0;
}

This produces:

11917834.814763514000000

Which looks correct to me. I'm using VC++ 2008 instead of 2005, but I'd guess the difference is in your code, not the compiler.