public string ExampleCalculation()
{
double h = 0.002, sum = 0, I;
CalculationEngine calculation = new CalculationEngine();
if (!ExpressionChanges.Check_string(expression))
{
return("error");
}
if (ExpressionChanges.IsEmpty(botLim) || ExpressionChanges.IsEmpty(upperLim))
{
return("error_Lim");
}
if (Double.Parse(botLim) > Double.Parse(upperLim))
{
return("error_Lim");
}
try
{
for (double Xi = Convert.ToDouble(botLim) + h; Xi < Convert.ToDouble(upperLim); Xi = Xi + h)
{
I = 0;
calculation.Variables["x"] = Xi;
I += (double)calculation.Evaluate(expression);
calculation.Variables["x"] = Xi - h;
I += (double)calculation.Evaluate(expression);
calculation.Variables["x"] = Xi - h / 2;
I += 4 * (double)calculation.Evaluate(expression);
sum += I;
}
}
catch (Exception e)
{
return("error");
}
double res = h / 6 * sum;
if (Double.IsNaN(res))
{
return("error_ODZ");
}
return(res.ToString());
}
static object CountIf(CalculationEngine ce, List <Expression> p)
{
var cnt = 0.0;
var ienum = p[0] as IEnumerable;
if (ienum != null)
{
var crit = (string)p[1].Evaluate();
foreach (var value in ienum)
{
if (!IsBlank(value))
{
var exp = string.Format("{0}{1}", value, crit);
if ((bool)ce.Evaluate(exp))
{
cnt++;
}
}
}
}
return(cnt);
}