Project Description
NCalc is a mathematical expressions evaluator in .NET. NCalc can parse any expression and evaluate the result, including static or dynamic parameters and custom functions.
For additional information on the technique we used to create this framework please read this article:
http://www.codeproject.com/KB/recipes/sota_expression_evaluator.aspx.
For documentation here is the table of content:
- description : overall concepts, usage and extensibility points
- operators : available standard operators and structures
- values : authorized values like types, functions, ...
- functions : list of already implemented functions
- parameters : on how to use parameters expressions
Functionnalities
Simple expressions
Expression e = new Expression("2 + 3 * 5");
Debug.Assert(17 == e.Evaluate());
Debug.Assert(123456 == new Expression("123456").Evaluate()); // integers
Debug.Assert(new DateTime(2001, 01, 01) == new Expression("#01/01/2001#").Evaluate()); // date and times
Debug.Assert(123.456 == new Expression("123.456").Evaluate()); // floating point numbers
Debug.Assert(true == new Expression("true").Evaluate()); // booleans
Debug.Assert("azerty" == new Expression("'azerty'").Evaluate()); // strings
Debug.Assert(0 == new Expression("Sin(0)").Evaluate());
Debug.Assert(2 == new Expression("Sqrt(4)").Evaluate());
Debug.Assert(0 == new Expression("Tan(0)").Evaluate());
Expression e = new Expression("SecretOperation(3, 6)");
e.EvaluateFunction += delegate(string name, FunctionArgs args)
{
if (name == "SecretOperation")
args.Result = (int)args.Parameters[0].Evaluate() + (int)args.Parameters[1].Evaluate();
};
Debug.Assert(9 == e.Evaluate());
Debug.Assert("経済協力開発機構" == new Expression("'経済協力開発機構'").Evaluate());
Debug.Assert("Hello" == new Expression(@"'\u0048\u0065\u006C\u006C\u006F'").Evaluate());
Debug.Assert("だ" == new Expression(@"'\u3060'").Evaluate());
Debug.Assert("\u0100" == new Expression(@"'\u0100'").Evaluate());
Expression e = new Expression("Round(Pow([Pi], 2) + Pow([Pi2], 2) + [X], 2)");
e.Parameters["Pi2"] = new Expression("Pi * [Pi]");
e.Parameters["X"] = 10;
e.EvaluateParameter += delegate(string name, ParameterArgs args)
{
if (name == "Pi")
args.Result = 3.14;
};
Debug.Assert(117.07 == e.Evaluate());
People behind NCalc
NCalc is a project managed by the people of Evaluant (
http://www.evaluant.com) and is a part of its R&D developments.
NCalc is a project managed by the people of
Evaluant and is a part of its
R&D developments