DoubleToSortableLong() public static method

Converts a double value to a sortable signed long. The value is converted by getting their IEEE 754 floating-point "double format" bit layout and then some bits are swapped, to be able to compare the result as long. By this the precision is not reduced, but the value can easily used as a long. The sort order (including Double#NaN) is defined by Double#compareTo; {@code NaN} is greater than positive infinity.
public static DoubleToSortableLong ( double val ) : long
val double
return long
NumericUtils Class Documentation
Exemplo n.º 1
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        public virtual void TestSortableDoubleNaN()
        {
            long plusInf = NumericUtils.DoubleToSortableLong(double.PositiveInfinity);

            foreach (double nan in DOUBLE_NANs)
            {
                Assert.IsTrue(double.IsNaN(nan));
                long sortable = NumericUtils.DoubleToSortableLong(nan);
                Assert.IsTrue((ulong)sortable > (ulong)plusInf, "Double not sorted correctly: " + nan + ", long repr: " + sortable + ", positive inf.: " + plusInf);
            }
        }
Exemplo n.º 2
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        public virtual void TestDoubles()
        {
            double[] vals     = new double[] { double.NegativeInfinity, -2.3E25, -1.0E15, -1.0, -1.0E-1, -1.0E-2, -0.0, +0.0, 1.0E-2, 1.0E-1, 1.0, 1.0E15, 2.3E25, double.PositiveInfinity, double.NaN };
            long[]   longVals = new long[vals.Length];

            // check forward and back conversion
            for (int i = 0; i < vals.Length; i++)
            {
                longVals[i] = NumericUtils.DoubleToSortableLong(vals[i]);
                Assert.IsTrue(vals[i].CompareTo(NumericUtils.SortableLongToDouble(longVals[i])) == 0, "forward and back conversion should generate same double");
            }

            // check sort order (prefixVals should be ascending)
            for (int i = 1; i < longVals.Length; i++)
            {
                Assert.IsTrue(longVals[i - 1] < longVals[i], "check sort order");
            }
        }