/// <summary>
/// Parse aproximation Z from string.
/// All required derivations are calculated automatically.
/// </summary>
/// <returns>
/// Instance of class if expression is correct math Z, othervise
/// returns null;
/// </returns>
public static AproximationFunction FromExpression(AproximationExpression expression)
{
var engine = new CalcEngine();
engine.Variables[expression.Var1] = 0.0d;
engine.Variables[expression.Var2] = 0.0d;
try
{
engine.Evaluate(expression.Expression);
}
catch (Exception)
{
return(null);
}
Func <double, double, double> function = (x, y) =>
{
engine.Variables[expression.Var1] = x;
engine.Variables[expression.Var2] = y;
var result = (double)engine.Evaluate(expression.Expression);
return(result);
};
return(new AproximationFunction(function));
}
public override MathFunction Interpret()
{
var calcEngine = new CalcEngine();
foreach (var variable in Variables)
{
calcEngine.Variables.Add(variable, 0);
}
return vals =>
{
for (var i = 0; i < vals.Length; i++)
{
calcEngine.Variables[Variables[i]] = vals[i];
}
return (double) calcEngine.Evaluate(Expression);
};
}
