public static void Investigations()
{
double geosyncOrbitR = 42000.0; // Real example, approximate geosynchronous orbit in km
double oneMillimeter = 1.0 / 1000.0 / 1000.0; // One mm in kilometers
Console.WriteLine("=========== Geosync Orbit plus 1/3 millimeter (and smaller) in kilometers ==========");
Console.WriteLine(" Objective is to have fractions of a millimeter correctly accumulate over many additions\n");
double large = geosyncOrbitR;
double small = oneMillimeter / 3.0;
Console.WriteLine("large: {0}, log10(large): {1:G5}\n", large, Math.Log10(Math.Abs(large)));
for (int i = 0; i < 200; i++)
{
Console.WriteLine("large + small ({0,22:G17}) = {1,22:G17} - sig digits in calc: {2}, log10(small): {3,7:G5}, logs difference: {4,6:G5} ({5}) (CAP V2: {6}, V3: {7})",
small, large + small, DecimalAdditionPrecision(large, small), Math.Log10(Math.Abs(small)),
Math.Log10(Math.Abs(large)) - Math.Log10(Math.Abs(small)), FloatingPointUtil.AdditionMagnitudeDifference(large, small),
FloatingPointUtil.CheckAdditionPrecisionV2(large, small), FloatingPointUtil.CheckAdditionPrecisionV3(large, small));
if (large + small == large)
{
break;
}
small *= 0.1;
}
}
public static void DisplayPrecisionIssue(double a, double b, string whichCalculation, int bodyNumber)
{
if (debugMessageCount++ < DebugMessageCountLimit)
{
Debug.WriteLine("Body #{4} {3}: a = {0:G17}, b = {1:G17}, mag diff = {2}", a, b, FloatingPointUtil.AdditionMagnitudeDifference(a, b), whichCalculation, bodyNumber);
}
if (debugMessageCount == DebugMessageCountLimit)
{
Debug.WriteLine(">>> Reached limit of {0:N0} precision warning messages. No more will be displayed.", DebugMessageCountLimit);
}
}