public void Atan2Benchmark()
{
var deltas = new List <decimal>();
var swf = new Stopwatch();
var swd = new Stopwatch();
foreach (var y in m_testCases)
{
foreach (var x in m_testCases)
{
for (int k = 0; k < 1000; ++k)
{
var yf = (Fix64)y;
var xf = (Fix64)x;
swf.Start();
var actualF = Fix64.Atan2(yf, xf);
swf.Stop();
swd.Start();
var expected = Math.Atan2((double)yf, (double)xf);
swd.Stop();
deltas.Add(Math.Abs((decimal)actualF - (decimal)expected));
}
}
}
Console.WriteLine("Max error: {0} ({1} times precision)", deltas.Max(), deltas.Max() / Fix64.Precision);
Console.WriteLine("Average precision: {0} ({1} times precision)", deltas.Average(), deltas.Average() / Fix64.Precision);
Console.WriteLine("Fix64.Atan2 time = {0}ms, Math.Atan2 time = {1}ms", swf.ElapsedMilliseconds, swd.ElapsedMilliseconds);
}
public void Atan2()
{
var maxDelta = 0.005m;
var deltas = new List <decimal>();
// Identities
Assert.Equal(Fix64.Atan2(Fix64.Zero, -Fix64.One), Fix64.Pi);
Assert.Equal(Fix64.Atan2(Fix64.Zero, Fix64.Zero), Fix64.Zero);
Assert.Equal(Fix64.Atan2(Fix64.Zero, Fix64.One), Fix64.Zero);
Assert.Equal(Fix64.Atan2(Fix64.One, Fix64.Zero), Fix64.PiOver2);
Assert.Equal(Fix64.Atan2(-Fix64.One, Fix64.Zero), -Fix64.PiOver2);
// Precision
for (var y = -1.0; y < 1.0; y += 0.01)
{
for (var x = -1.0; x < 1.0; x += 0.01)
{
var yf = (Fix64)y;
var xf = (Fix64)x;
var actual = (decimal)Fix64.Atan2(yf, xf);
var expected = (decimal)Math.Atan2((double)yf, (double)xf);
var delta = Math.Abs(actual - expected);
deltas.Add(delta);
Assert.True(delta <= maxDelta, string.Format("Precision: Atan2({0}, {1}): expected {2} but got {3}", yf, xf, expected, actual));
}
}
// Scalability and edge cases
foreach (var y in m_testCases)
{
foreach (var x in m_testCases)
{
var yf = (Fix64)y;
var xf = (Fix64)x;
var actual = (decimal)Fix64.Atan2(yf, xf);
var expected = (decimal)Math.Atan2((double)yf, (double)xf);
var delta = Math.Abs(actual - expected);
deltas.Add(delta);
Assert.True(delta <= maxDelta, string.Format("Scalability: Atan2({0}, {1}): expected {2} but got {3}", yf, xf, expected, actual));
}
}
output.WriteLine("Max error: {0} ({1} times precision)", deltas.Max(), deltas.Max() / Fix64.Precision);
output.WriteLine("Average precision: {0} ({1} times precision)", deltas.Average(), deltas.Average() / Fix64.Precision);
}
public static Fix64 Atan2(Fix64 y, Fix64 x)
{
//return Math.Atan2(y.ToDouble(), x.ToDouble());
return(Fix64.Atan2(y, x));
}