private void CreateResultFormula(string formula)
{
if (string.IsNullOrEmpty(formula)) return;
MathFormula = formula;
var engine = new CalculationEngine(CultureInfo.InvariantCulture);
var formulaBuilder = engine.Formula(mathFormula).Result(Jace.DataType.FloatingPoint);
var variable = 'a';
for (var i = 0; i < criteria.Count; i++)
formulaBuilder.Parameter("" + variable++, Jace.DataType.FloatingPoint);
resultFormula = formulaBuilder.Build();
}
/// <summary>
/// Converts the formula to a standard form, i.e.
/// {4}*{5} => a*b
/// Where
/// a is inputParameters[0],
/// b is inputParameters[1], etc.
/// </summary>
private object MathFormula(IReadOnlyList<SqlInputParameter> sqlInputParameters)
{
if (currentMathFormula != null) return currentMathFormula;
inputParameters.Clear();
var parameter = 'a';
var formula = DesiredResultFormula;
var index = 0;
while (formula.Contains("{") && index < sqlInputParameters.Count)
{
var lookFor = string.Format("{{{0}}}", index++); // {0}, {1} etc.
if (!formula.Contains(lookFor)) continue;
formula = formula.Replace(lookFor, "" + parameter++);
inputParameters.Add(sqlInputParameters[index-1]);
}
var engine = new CalculationEngine(CultureInfo.InvariantCulture);
var formulaBuilder = engine.Formula(formula).Result(DataType.FloatingPoint);
parameter = 'a';
for (var i = 0; i < inputParameters.Count; i++)
formulaBuilder.Parameter("" + parameter++, DataType.FloatingPoint);
return currentMathFormula = formulaBuilder.Build();
}