Addition / Sum Bug

[Former user]

Try evaluating "23.1+78.2" and it equals "101.30000000000001". I tried it with similar numbers and it seems to do it with a variety of numbers with ".1" and ".2"

[Axel Kramer]

This is due to how floating point arithmetic works in Java (or other programming languages): You can try the following example:

public class DoubleTest {
    public static void main(String[] args) {
        double v1 = 23.1;
        double v2 = 87.2;
        double v3 = v1 + v2;
        // prints: 110.30000000000001
        System.out.println(v3);

    }
}

See these questions on stackoverflow.com:

• Floating point arithmetic not producing exact results

• Java floats and doubles...

[jim bob]

Any way you can use BigDecimal? Or would that conflict with something? Let me know the section that would need changing. I could contribute.

[Axel Kramer]

Commons math uses double types in almost all of the algorithms.

On the other side maybe the commons math Dfp numbers may match your requirements?

Dfp Decimal floatng point library

[jim bob]

That looks good, I'll make a fork in the coming days