C++ Numerical truncation error
- by Andrew
Hello everyone,
sorry if dumb but could not find an answer.
#include <iostream>
using namespace std;
int main()
{
double a(0);
double b(0.001);
cout << a - 0.0 << endl;
for (;a<1.0;a+=b);
cout << a - 1.0 << endl;
for (;a<10.0;a+=b);
cout << a - 10.0 << endl;
cout << a - 10.0-b << endl;
return 0;
}
Output:
0
6.66134e-16
0.001
-1.03583e-13
Tried compiling it with MSVC9, MSVC10, Borland C++ 2010. All of them arrive in the end to the error of about 1e-13.
Is it normal to have such a significant error accumulation over only a 1000, 10000 increments?
