public override double EvaluateVarFunction(VarFuncToken token)
{
Func <double, double> func;
int start;
switch (token.Symbol)
{
case ParserSymbols.Sum:
func = ExpressionTreeEvaluator.CreateDelegate(token.SubTokens[3],
token.VariableSymbol, parser, Context.Options);
start = (int)eval(token.SubTokens[1]);
return(Enumerable.Range(start, (int)eval(token.SubTokens[2]) - start + 1)
.Select(v => func(v)).Sum());
case ParserSymbols.Prod:
func = ExpressionTreeEvaluator.CreateDelegate(token.SubTokens[3],
token.VariableSymbol, parser, Context.Options);
start = (int)eval(token.SubTokens[1]);
return(Enumerable.Range(start, (int)eval(token.SubTokens[2]) - start + 1)
.Select(v => func(v))
.Aggregate((v1, v2) => v1 * v2));
default:
if (Context.Options.StrictMode)
{
throw new UnsupportedOperationException(token.Symbol);
}
return(double.NaN);
}
}
public override BigDecimal EvaluateVarFunction(VarFuncToken token)
{
if (Context.Options.StrictMode)
{
throw new UnsupportedOperationException(token.Symbol);
}
double result = token.Evaluate(fallback);
if (double.IsNaN(result))
{
throw new ParserArithmeticException(token.Position);
}
else
{
return(result);
}
}
public override string EvaluateVarFunction(VarFuncToken token)
{
string symbol = String.Empty;
switch (token.Symbol)
{
case ParserSymbols.Sum:
symbol = "∑";
break;
case ParserSymbols.Prod:
symbol = "∏";
break;
}
var sb = new StringBuilder($"<munderover><mo>{symbol}</mo>");
sb.AppendFormat("<mrow><mi>{0}</mi><mo>=</mo>{1}</mrow>",
token.VariableSymbol, evalSub(token, 1));
sb.AppendFormat("<mrow>{0}</mrow></munderover>", evalSub(token, 2));
sb.AppendFormat("<mrow>{0}</mrow>", evalSub(token, 3));
return(sb.ToString());
}
public override Expression EvaluateVarFunction(VarFuncToken token)
{
Func <double, double> func;
switch (token.Symbol)
{
case ParserSymbols.Sum:
func = ExpressionTreeEvaluator.CreateDelegate(token.SubTokens[3],
token.VariableSymbol, parser, Context.Options);
return(iterateExpr(0, token.SubTokens[1], token.SubTokens[2], (v, i) => v + func(i)));
case ParserSymbols.Prod:
func = ExpressionTreeEvaluator.CreateDelegate(token.SubTokens[3],
token.VariableSymbol, parser, Context.Options);
return(iterateExpr(1, token.SubTokens[1], token.SubTokens[2], (v, i) => v * func(i)));
default:
if (Context.Options.StrictMode)
{
throw new UnsupportedOperationException(token.Symbol);
}
return(Expression.Constant(double.NaN));
}
}
/// <summary> /// Evaluates a given iteration function token. /// </summary> /// <param name="token">The token to be evaluated.</param> /// <returns>The evaluated value.</returns> public abstract T EvaluateVarFunction(VarFuncToken token);
public override string EvaluateVarFunction(VarFuncToken token) => EvaluateFunction(token);
