public void Overlapping_AreNot_NonOverlapping()
{
var d1 = DoubleConverter.FromFloatingPointBinaryString("101");
var d2 = DoubleConverter.FromFloatingPointBinaryString("10");
Assert.IsFalse(ExpansionExtensions.AreNonOverlapping(d1, d2));
}
public void NonOverlapping_Are_NonOverlapping()
{
var d1 = DoubleConverter.FromFloatingPointBinaryString("1100");
var d2 = DoubleConverter.FromFloatingPointBinaryString("-10.1");
Assert.IsTrue(ExpansionExtensions.AreNonOverlapping(d1, d2));
}
public void StronglyNonOverlapping()
{
// Two examples that are strongly nonoverlapping (S.p12)
var sn1 = new[] { DoubleConverter.FromFloatingPointBinaryString("11000"),
DoubleConverter.FromFloatingPointBinaryString("11") };
var sn2 = new[] { DoubleConverter.FromFloatingPointBinaryString("10000"),
DoubleConverter.FromFloatingPointBinaryString("1000"),
DoubleConverter.FromFloatingPointBinaryString("10"),
DoubleConverter.FromFloatingPointBinaryString("1") };
Assert.IsTrue(sn1.IsStronglyNonOverlapping());
Assert.IsTrue(sn2.IsStronglyNonOverlapping());
// Two examples that are _not_ strongly nonoverlapping (S.p12)
var nsn1 = new[] { DoubleConverter.FromFloatingPointBinaryString("11100"),
DoubleConverter.FromFloatingPointBinaryString("11") };
var nsn2 = new[] { DoubleConverter.FromFloatingPointBinaryString("100"),
DoubleConverter.FromFloatingPointBinaryString("10"),
DoubleConverter.FromFloatingPointBinaryString("1") };
Assert.IsFalse(nsn1.IsStronglyNonOverlapping());
Assert.IsFalse(nsn2.IsStronglyNonOverlapping());
}
public void BitWidth_Large()
{
double d = DoubleConverter.FromFloatingPointBinaryString("1010101" + '0'.Repeat(200));
int width = d.BitWidth();
Assert.AreEqual(7, width);
}
public void ShowDoubleRoundingPriestExplicit()
{
double a = DoubleConverter.FromFloatingPointBinaryString("1" + '0'.Repeat(51) + "1"); // 100....00001 (53-bits wide)
double b = DoubleConverter.FromFloatingPointBinaryString("0.0" + '1'.Repeat(53)); // 0.0111...111 (53 1's)
double expected53 = a;
double expected64 = a + 1.0; // The point is that this is different to expceted53.
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(a));
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(b));
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(expected53));
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(expected64));
// Set Fpu to 53-bit precision (the default)
FpuControl.SetState((uint)FpuControl.PrecisionControl.Double53Bits, FpuControl.Mask.PrecisionControl);
double result53 = a + b;
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(result53));
Assert.AreEqual(expected53, result53);
// Explicit rounding makes no difference here (since we're in Double53bits precision FPU mode)
result53 = (double)(a + b);
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(result53));
Assert.AreEqual(expected53, result53);
// Set Fpu to 64-bit precision (extended precision)
FpuControl.SetState((uint)FpuControl.PrecisionControl.Extended64Bits, FpuControl.Mask.PrecisionControl);
double result64 = (double)(a + b);
Debug.Print(DoubleConverter.ToFloatingPointBinaryString(result64));
Assert.AreEqual(expected64, result64);
}
public void OptimTest()
{
// 53 ones
string a_s = "11111111111111111111111111111111111111111111111111110.0";
double a = DoubleConverter.FromFloatingPointBinaryString("11111111111111111111111111111111111111111111111111110.0");
double b = DoubleConverter.FromFloatingPointBinaryString("-11111111111111111111111111111111111111111111111111110.0");
double c = DoubleConverter.FromFloatingPointBinaryString("00000000000000000000000000000000000000000000000000000.01");
string a_s2 = DoubleConverter.ToFloatingPointBinaryString(9.0071992547409900e+0015);
Assert.AreEqual(a_s, a_s2);
bool ok = Test(a, b, c);
Assert.IsTrue(ok);
double acc = TestAcc(a, b, c);
double acc2 = TestAcc(a, b, c);
if (acc != acc2)
{
Assert.Fail();
}
Assert.AreEqual(0.0, acc);
Assert.AreEqual(0.0, acc2);
double tst2 = Test2(a, b, c);
if (tst2 != 0.0)
{
Assert.Fail();
}
}
public void ShowDoubleRounding()
{
double a = DoubleConverter.FromFloatingPointBinaryString('1'.Repeat(52) + "0"); // 111....11110
double b = DoubleConverter.FromFloatingPointBinaryString("0.100000000001"); // 000....00000.100000000001
double expected53 = DoubleConverter.FromFloatingPointBinaryString('1'.Repeat(52) + "1"); // 111....11111
double expected64 = a;
// Set Fpu to 53-bit precision (the default)
FpuControl.SetState((uint)FpuControl.PrecisionControl.Double53Bits, FpuControl.Mask.PrecisionControl);
double result53 = a + b;
Assert.AreEqual(expected53, result53);
// Set Fpu to 64-bit precision (extended precision)
FpuControl.SetState((uint)FpuControl.PrecisionControl.Extended64Bits, FpuControl.Mask.PrecisionControl);
double result64 = (double)(a + b);
Assert.AreEqual(expected64, result64);
double result64_0 = (a + b) - a;
Assert.AreNotEqual(0.0, result64_0);
Assert.AreNotEqual(b, result64_0);
Assert.AreEqual(0.5, result64_0); // 000....00000.1
}
public void BitWidth_Simple()
{
double d = DoubleConverter.FromFloatingPointBinaryString("-0.001010101000");
int width = d.BitWidth();
Assert.AreEqual(7, width);
}
public void Split_Simple()
{
double d = DoubleConverter.FromFloatingPointBinaryString("-0.001010101000");
double ahi;
double alo;
Split_Checked(d, out ahi, out alo);
}
// Here we add an explicit cast, which ensures that (a + b) is evaluated to 64-bits before continuing
public double TestCalcSafe()
{
double a = DoubleConverter.FromFloatingPointBinaryString("11111111111111111111111111111111111111111111111111110.0");
double b = DoubleConverter.FromFloatingPointBinaryString("00000000000000000000000000000000000000000000000000000.1");
double result = (double)(a + b) - a;
return(result);
}
public void Split_FullPrecision()
{
var dstr = "1." + '1'.Repeat(52);
double d = DoubleConverter.FromFloatingPointBinaryString(dstr);
var dstr2 = d.ToFloatingPointBinaryString();
NUnit.Framework.Assert.AreEqual(dstr, dstr2);
double ahi;
double alo;
Split_Checked(d, out ahi, out alo);
}
public void FastTwoSum_OppositeSign()
{
// Adapted example from Shewchuk p. 7 - Figure 4 - expanded to double
// We expect a+b=x+y
double a = DoubleConverter.FromFloatingPointBinaryString("1" + '0'.Repeat(51) + "10"); // 100...0010
double b = DoubleConverter.FromFloatingPointBinaryString("-" + '1'.Repeat(49) + "1011"); // -11...1011
double x_correct = DoubleConverter.FromFloatingPointBinaryString("111"); // 111
double y_correct = 0.0;
double x; double y;
EA.FastTwoSum(a, b, out x, out y);
Assert.AreEqual(x_correct, x);
Assert.AreEqual(y_correct, y);
}
public void Split_FullPrecisionLarge()
{
// -1111...(53)...11111000000....000000000
var dstr = "-1" + '1'.Repeat(52) + '0'.Repeat(200);
double d = DoubleConverter.FromFloatingPointBinaryString(dstr);
var dstr2 = d.ToFloatingPointBinaryString();
NUnit.Framework.Assert.AreEqual(DoubleConverter.FromFloatingPointBinaryString(dstr),
DoubleConverter.FromFloatingPointBinaryString(dstr2));
double ahi;
double alo;
Split_Checked(d, out ahi, out alo);
}
public void TwoSum_Small_a()
{
// This is an example that FastTwoSum gets wrong (|a|<|b|), but TwoSum does right
// Shewchuck p. 8, Figure 5
double a = DoubleConverter.FromFloatingPointBinaryString('1'.Repeat(51) + ".11"); // 111...111.11
double b = DoubleConverter.FromFloatingPointBinaryString("110" + '0'.Repeat(49) + "1"); // 11000...001
double x_correct = DoubleConverter.FromFloatingPointBinaryString("1" + '0'.Repeat(53)); // 100000...000
double y_correct = DoubleConverter.FromFloatingPointBinaryString("0.11"); // 0.11
double x; double y;
EA.TwoSum(a, b, out x, out y);
Assert.AreEqual(x_correct, x);
Assert.AreEqual(y_correct, y);
}
public void FastTwoSum_SameSign()
{
// Example ismilar to Shewchuk p. 7 - Figure 3 (expanded for double)
// We expect a+b=x+y
double a = DoubleConverter.FromFloatingPointBinaryString('1'.Repeat(53) + "00"); // 1111...1100
double b = DoubleConverter.FromFloatingPointBinaryString("1001"); // 1001
double x_correct = DoubleConverter.FromFloatingPointBinaryString("1" + '0'.Repeat(51) + "1000"); // 1000...00100
double y_correct = DoubleConverter.FromFloatingPointBinaryString("-11"); // - 11
double x; double y;
EA.FastTwoSum(a, b, out x, out y);
Assert.AreEqual(x_correct, x);
Assert.AreEqual(y_correct, y);
}
public void RoundToEvenTiebreaking()
{
var d1 = DoubleConverter.FromFloatingPointBinaryString("100000000000000000000000000000000000000000000000000010");
var d2 = DoubleConverter.FromFloatingPointBinaryString("1");
// Closest even to ~~~011
var d3 = DoubleConverter.FromFloatingPointBinaryString("100000000000000000000000000000000000000000000000000100");
var dtest = (double)d1 + d2;
var stest = dtest.ToFloatingPointBinaryString();
Assert.AreEqual(d3, dtest);
// Closest even to ~~~001
var d4 = DoubleConverter.FromFloatingPointBinaryString("100000000000000000000000000000000000000000000000000000");
var dtest2 = (double)d1 - d2;
var stest2 = dtest2.ToFloatingPointBinaryString();
Assert.AreEqual(d4, dtest2);
}
public void TestPrecision53()
{
double a = DoubleConverter.FromFloatingPointBinaryString('1'.Repeat(52) + "0"); // 111....11110
double b = DoubleConverter.FromFloatingPointBinaryString("0.1"); // 000....00000.1
double expected53 = a;
FpuControl.SetState((uint)FpuControl.PrecisionControl.Double53Bits, FpuControl.Mask.PrecisionControl);
double result53 = (double)(a + b);
Assert.AreEqual(expected53, result53);
double result53_0 = (a + b) - a;
Assert.AreEqual(0.0, result53_0);
double result53_X = ((double)(a + b)) - a;
Assert.AreEqual(0.0, result53_X);
}
public void TestPrecision64()
{
double a = DoubleConverter.FromFloatingPointBinaryString('1'.Repeat(52) + "0"); // 111....11110
double b = DoubleConverter.FromFloatingPointBinaryString("0.1"); // 000....00000.1
double expected64 = a;
FpuControl.SetState((uint)FpuControl.PrecisionControl.Extended64Bits, FpuControl.Mask.PrecisionControl);
double result64 = (double)(a + b);
Assert.AreEqual(expected64, result64);
double result64_b = (a + b) - a;
Assert.AreEqual(b, result64_b);
double result64_0 = ((double)(a + b)) - a;
Assert.AreNotEqual(b, result64_0);
Assert.AreEqual(0.0, result64_0);
}
public void FloatingPointBinaryString_MatchesValue()
{
var tests = new[]
{
Tuple.Create(4.0, "100.0"),
Tuple.Create(0.25, "0.01"),
Tuple.Create(0.0, "0.0"),
Tuple.Create(-2.5, "-10.1"),
Tuple.Create(double.MaxValue, "1111111111111111111111111111111111111111111111111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.0"),
Tuple.Create(double.MinValue, "-1111111111111111111111111111111111111111111111111111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.0"),
Tuple.Create(double.Epsilon, "0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001"),
Tuple.Create(DoubleEpsilonSplitter().Item1, "0.00000000000000000000000000000000000000000000000000001"), // biggest exponent of 2 s.t. 1.0 + eps = 1.0
};
foreach (var t in tests)
{
string r = DoubleConverter.ToFloatingPointBinaryString(t.Item1);
Assert.AreEqual(t.Item2, r);
double d = DoubleConverter.FromFloatingPointBinaryString(r);
Assert.AreEqual(t.Item1, d);
}
}