/// <summary>
 /// inject one formula
 /// </summary>
 /// <param name="formula"></param>
 public void Inject(FunctionFormula formula)
 {
     Formulas.Add(formula);
 }
        /// <summary>
        /// inject formula by base datas
        /// </summary>
        /// <param name="formula"></param>
        /// <param name="lineColor"></param>
        /// <param name="lineWidth"></param>
        public void Inject(Func <float, float> formula, Color lineColor, float lineWidth = 2.0f)
        {
            var functionalFormula = new FunctionFormula(formula, lineColor, lineWidth);

            Inject(functionalFormula);
        }