ChiSquare.cs

using System;
using System.Text;
using Waher.Content;
using Waher.Script.Statistics;
 
namespace TAG.Simulator.ObjectModel.Distributions
{
    public class ChiSquare : Chi
    {
        public ChiSquare(ISimulationNode Parent, Model Model)
            : base(Parent, Model)
        {
        }
 
        public override string LocalName => nameof(ChiSquare);
 
        public override ISimulationNode Create(ISimulationNode Parent, Model Model)
        {
            return new ChiSquare(Parent, Model);
        }
 
        protected override double GetCumulativeProbability(double t, int NrCycles)
        {
            t -= this.t0;
            if (t < 0)
                return 0;
            else
                return StatMath.γ(this.kHalf, t / 2) * this.c;
        }
 
        public override void ExportPdfBody(StringBuilder Output)
        {
            Output.Append("t<");
            Output.Append(CommonTypes.Encode(this.t0));
            Output.Append("?0:");
            Output.Append(CommonTypes.Encode(this.c * Math.Pow(2, -this.kHalf)));
            Output.Append("*(t-");
            Output.Append(CommonTypes.Encode(this.t0));
            Output.Append(").^");
            Output.Append(CommonTypes.Encode(this.kHalf - 1));
            Output.Append(".*exp(-(t-");
            Output.Append(CommonTypes.Encode(this.t0));
            Output.Append(")/2)");
        }
 
    }
}