public void CosPITest()
{
foreach (MultiPrecision <Pow2.N8> x in TestTool.ShortRangeSet <Pow2.N8>())
{
MultiPrecision <Pow2.N8> y = MultiPrecision <Pow2.N8> .CosPI(x);
Console.WriteLine(x);
Console.WriteLine(y);
TestTool.Tolerance(Math.Cos((double)x * Math.PI), y, minerr: 1e-5, ignore_sign: true);
}
}