/// <summary>
/// Calculate the Chebyshev measure for the given set of elements.
/// </summary>
/// <param name="elements"></param>
/// <returns></returns>
public float Calculate(ICollection <Utility> elements)
{
var wsum = 0.0f;
int count = elements.Count;
if (count == 0)
{
return(0.0f);
}
foreach (var el in elements)
{
wsum += el.Weight;
}
if (CrMath.AeqZero(wsum))
{
return(0.0f);
}
var vlist = new List <float>(count);
foreach (var el in elements)
{
vlist.Add(el.Value * (el.Weight / wsum));
}
var ret = vlist.Max <float>();
return(ret);
}
/// <summary>
/// Chebyshev norm for the given utility list.
/// </summary>
/// <param name="this">Utility list.</param>
public static float Chebyshev(this ICollection <Utility> @this)
{
if (@this.Count == 0)
{
return(0.0f);
}
var wsum = @this.SumWeights();
if (CrMath.AeqZero(wsum))
{
return(0.0f);
}
var vlist = new List <float>(@this.Count);
foreach (var util in @this)
{
var v = util.Value * (util.Weight / wsum);
vlist.Add(v);
}
var ret = vlist.Max <float>();
return(ret);
}
/// <summary>
/// Calculate the l-p weighted metrics measure for the given set of elements.
/// </summary>
/// <param name="elements"></param>
/// <returns></returns>
public float Calculate(ICollection <Utility> elements)
{
var count = elements.Count;
if (count == 0)
{
return(0.0f);
}
var wsum = 0.0f;
foreach (var el in elements)
{
wsum += el.Weight;
}
if (CrMath.AeqZero(wsum))
{
return(0.0f);
}
var vlist = new List <float>(count);
foreach (var el in elements)
{
var v = el.Weight / wsum * (float)Math.Pow(el.Value, _p);
vlist.Add(v);
}
var sum = vlist.Sum();
var res = (float)Math.Pow(sum, _oneOverP);
return(res);
}
/// <summary>
/// Rescales the given value to the interval [0,1]. If the value is smaller than min, it will be
/// clamped to min and if the value is larger than max it will be clamped to max.
/// WARNING: Never use this extension like this: 1.0.Normalize(min, max), since if the value is negative
/// the sign (if there is one) will not be passed to the extension method leading to unexpected results.
/// </summary>
public static double Normalize01(this double @this, double min, double max)
{
@this = @this.Clamp <double>(min, max);
@this = @this - min;
var df = max - min;
if (CrMath.AeqZero(df))
{
throw new MinEqualMaxException();
}
return(@this / df);
}
/// <summary>
/// Rescales the given value to the interval [0,1]. If the value is smaller than min, it will be
/// clamped to min and if the value is larger than max it will be clamped to max.
/// WARNING: Never use this extension like this: 1.0f.Normalize01(min, max), since if the value is negative
/// the sign (if there is one) will not be passed to the extension method leading to unexpected results.
/// </summary>
public static float Normalize01(this float @this, float min, float max)
{
@this = @this.Clamp <float>(min, max);
@this = @this - min;
var df = max - min;
if (CrMath.AeqZero(df))
{
throw new MinEqualMaxException();
}
return(@this / df);
}