namespace Exocortex.DSP
{
    public class SimplePolynomial : Polynomial
    {
        public SimplePolynomial(params double[] coefficients) : base(coefficients) { }

        public override double Evaluate(double value)
        {
            var retval = coefficients[0];
            var f = value;

            for (int i = 1; i < coefficients.Length; i++)
            {
                retval += coefficients[i] * f;
                f *= value;
            }
            return retval;
        }
    }
    public abstract class Polynomial
    {
        public Polynomial(params double[] coefficients)
        {
            this.coefficients = new double[coefficients.Length];

            for (int i = 0; i < coefficients.Length; i++)
                this.coefficients[i] = coefficients[i];
        }

        public abstract double Evaluate(double value);

        protected double[] coefficients = null;

        public double GetCoefficient(int index)
        {
            if (null == coefficients || index < 0 || index >= coefficients.Length)
            {
                return double.NaN;
            }
            return coefficients[index];
        }
    }
}