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Sander Rossel wrote:

so always treat it as smallest value, or always as biggest value or, better yet, throw an exception when comparing it to numbers.

BillWoodruff wrote:

that implies the treatment of double.NaN in the 'Min function is different than in the 'Max function

BillWoodruff wrote:

it was the contemplation of the mathematics of the ordinality of infinities (the aleph) that drove both Cantor, and Godel, insane

BillWoodruff wrote:

that implies the treatment of double.NaN in the 'Min function is different than in the 'Max function.

if (currentMin > values[i])
  currentMin = values[i];

if (!(currentMax > values[i]))
  currentMax = values[i];

if (currentMax < values[i])
  currentMax = values[i];

// Normally NaN < anything is false, as is anything < NaN
// However, this leads to some irksome outcomes in Min and Max.
// If we use those semantics then Min(NaN, 5.0) is NaN, but
// Min(5.0, NaN) is 5.0!  To fix this, we impose a total
// ordering where NaN is smaller than every value, including
// negative infinity.
if (x < value || System.Single.IsNaN(x)) value = x;

Mladen Janković wrote:

I'll be damned. NaN indeed has different treatment

Sander Rossel wrote:

NaN will behave differently, feels very random.

namespace CatState
{
    public static class CatStateExtensions
    {    
        public static double CatDead(this double[] args)
        {
            if (args.Contains(double.NaN))
            {
                Random rnd = new Random((int) DateTime.Now.Ticks);

                return (rnd.Next(0,2) == 0)
                    ? double.PositiveInfinity
                    : double.NegativeInfinity;
            }

            return args.Min();
        }

        public static double CatAlive(this double[] args)
        {
            if (args.Contains(double.NaN))
            {
                Random rnd = new Random((int) DateTime.Now.Ticks);

                return (rnd.Next(0,2) == 1)
                    ? double.PositiveInfinity
                    : double.NegativeInfinity;
            }

            return args.Max();
        }
    }
}

BillWoodruff wrote:

Random rnd = new Random((int) DateTime.Now.Ticks);

BillWoodruff wrote:

I wrote that code while I was half-dead, although that's a very poor excuse

Jochen Arndt wrote:

The implementation of Min and Max is probably not. But a Min function is usually implemented as
x < y ? x : y
instead of
!(x >= y) ? x : y

// Normally NaN < anything is false, as is anything < NaN
// However, this leads to some irksome outcomes in Min and Max.
// If we use those semantics then Min(NaN, 5.0) is NaN, but
// Min(5.0, NaN) is 5.0!  To fix this, we impose a total
// ordering where NaN is smaller than every value, including
// negative infinity.