/// <summary>
/// Computes unbiased variance from all elements of the <paramref name="ndArray"/>.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="ndArray"></param>
/// <returns></returns>
public static T UnbiasedVar <T>(this INdArray <T> ndArray)
{
var value = ValueTrait.Zero <T>();
var mean = ndArray.Mean();
var len = ndArray.Shape.TotalLength;
for (var i = 0; i < len; ++i)
{
var temp = ValueTrait.Subtract(ndArray.GetItem(i), mean);
value = ValueTrait.Multiply(temp, temp);
}
return(ValueTrait.Divide(value, ValueTrait.FromLong <T>(len - 1)));
}
/// <summary> /// Computes mean from all elements of the <paramref name="ndArray"/>. /// </summary> /// <typeparam name="T"></typeparam> /// <param name="ndArray"></param> /// <returns></returns> public static T Mean <T>(this INdArray <T> ndArray) => ValueTrait.Divide(ndArray.Sum(), ValueTrait.FromLong <T>(ndArray.Shape.TotalLength));