Rank.cs

using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Functions.Matrices
{
    public class Rank : FunctionOneVariable
    {
        public Rank(ScriptNode Argument, int Start, int Length, Expression Expression)
            : base(Argument, Start, Length, Expression)
        {
        }
 
        public override string FunctionName => nameof(Rank);
 
        public override IElement Evaluate(IElement Argument, Variables Variables)
        {
            if (Argument is IMatrix M)
            {
                if (M.Reduce(false, false, out int Rank, out _) is null || Rank < 0)
                    throw new ScriptRuntimeException("Unable to compute rank of matrix.", this);
 
                return new DoubleNumber(Rank);
            }
            else
                throw new ScriptRuntimeException("Expected matrix argument.", this);
        }
    }
}