DotProduct.cs

using System.Collections.Generic;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
 
namespace Waher.Script.Operators.Vectors
{
    public class DotProduct : BinaryVectorOperator
    {
        public DotProduct(ScriptNode Left, ScriptNode Right, int Start, int Length, Expression Expression)
            : base(Left, Right, Start, Length, Expression)
        {
        }
 
        public override IElement EvaluateVector(IVector Left, IVector Right, Variables Variables)
        {
            if (Left.Dimension != Right.Dimension)
                throw new ScriptRuntimeException("Vectors of different dimensions.", this);
 
            IEnumerator<IElement> e1 = Left.VectorElements.GetEnumerator();
            IEnumerator<IElement> e2 = Right.VectorElements.GetEnumerator();
            IElement Result = null;
 
            try
            {
                while (e1.MoveNext() && e2.MoveNext())
                {
                    if (Result is null)
                        Result = Arithmetics.Multiply.EvaluateMultiplication(e1.Current, e2.Current, this);
                    else
                    {
                        Result = Arithmetics.Add.EvaluateAddition(Result,
                            Arithmetics.Multiply.EvaluateMultiplication(e1.Current, e2.Current, this), this);
                    }
                }
 
                if (Result is null)
                    throw new ScriptRuntimeException("Cannot operate on zero-dimension vectors.", this);
 
                return Result;
            }
            finally
            {
                e1.Dispose();
                e2.Dispose();
            }
        }
 
    }
}