ProbabilityWindow.cs

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using System;
using AnalyzeRe.Attributes;
 
namespace AnalyzeRe
{
    public class ProbabilityWindow : APIType, IEquatable<ProbabilityWindow>
    {
        #region Private Fields
        private readonly int _minTrialSelection;
 
        private readonly int _maxTrialSelection;
 
        // The cached computed hash value for this probability window.
        private readonly int _hashValue;
        #endregion Private Fields
 
        [GreaterThan(0, true), LessThan(1, false)]
        public double min_probability { get; }
 
        [GreaterThan(0, false), LessThan(1, true)]
        public double max_probability { get; }
 
        public ProbabilityWindow(double min, double max)
        {
            min_probability = min;
            max_probability = max;
            if (min < 0)
                throw new ArgumentOutOfRangeException(nameof(min), min,
                    "The min probability must be greater than or equal to zero. The range is [0,1)");
            if (min >= 1)
                throw new ArgumentOutOfRangeException(nameof(min), min,
                    "The min probability must be less than one. The range is [0,1)");
            if (max <= 0)
                throw new ArgumentOutOfRangeException(nameof(max), max,
                    "The max probability must be greater than zero. The range is (0,1]");
            if (max > 1)
                throw new ArgumentOutOfRangeException(nameof(max), max,
                    "The max probability must be less than or equal to one. The range is (0,1]");
            if (max < min)
                throw new ArgumentOutOfRangeException(nameof(max), max,
                    "The max probability must be greater or equal to than the min probability.");
            // Compute internal properties used for optimal hashing and equivalence
            _minTrialSelection = (int)(min * Int32.MaxValue);
            _maxTrialSelection = (int)(max * Int32.MaxValue);
            _hashValue = new { _minTrialSelection, _maxTrialSelection }.GetHashCode();
        }
 
        #region Public Static Factory Methods
        public static ProbabilityWindow All => new ProbabilityWindow(0, 1);
 
        public static ProbabilityWindow Tail(double tail_probability) => new ProbabilityWindow(0, tail_probability);
 
        public static ProbabilityWindow FromReturnPeriods(double starting_return_period, double ending_return_period) =>
            new ProbabilityWindow(1d / ending_return_period, 1d / starting_return_period);
 
        [Obsolete("Warning: This implicit conversion will be deprecated. You should explicitly create a probability " +
            "window for a tail distribution using ProbabilityWindow.Tail if that is your intention.")]
        public static implicit operator ProbabilityWindow(double tail) => Tail(tail);
        #endregion Public Static Factory Methods
 
        #region IEquatable Implementation
        public bool Equals(ProbabilityWindow other) => other != null &&
            _minTrialSelection == other._minTrialSelection && _maxTrialSelection == other._maxTrialSelection;
 
        public override bool Equals(object obj) => obj is ProbabilityWindow pw && Equals(pw);
 
        public override int GetHashCode() => _hashValue;
        #endregion IEquatable Implementation
 
        public override string ToString() => $"{min_probability:R}_{max_probability:R}";
    }
}