AForge.Math.PerlinNoise.Function C# (CSharp) Method

        public double Function( double x )
        {
            double	frequency = initFrequency;
            double	amplitude = initAmplitude;
            double	sum = 0;

            // octaves
            for ( int i = 0; i < octaves; i++ )
            {
                sum += SmoothedNoise( x * frequency ) * amplitude;

                frequency *= 2;
                amplitude *= persistence;
            }
            return sum;
        }