Question

This is a piece of my code, it is called every second, after about 10 seconds the values start to become weird (see below):

double a;
double b;

for (int i = 0; i < currAC.Length; i++ )
{                 
    a = currAC[i];
    b = aveACValues[i];
    divisor = (a/b);
    Console.WriteLine("a = " + a.ToString("N2") + "\t" + "b = " + b.ToString("N2"));
    Console.WriteLine("divisor = " + divisor);
    Console.WriteLine("a+b = " + (a+b));
}

and the output:

a = -0.05 b = 0.00

divisor = 41

a+b = -0.0524010372273268

currAC and aveACValues are double[]

what on earth is going on???? The addition result is correct every time, but the division value is wrong, yet it is reading a and b correctly??

EDIT: ’41’ is the value of the first calculation, ie when a = currAC[0], but this should not remain???

Answer 1

if b == -0.001219512195122, then a/b==41, and a+b==-0.051219512195122 – so something around those areas (rounding etc) sounds feasible…

Also; note that for some arithmetic, it is possible it is using values that are still in registers. Registers may exhibit slightly different accuracy (and so give different results) than local variables.