2.0.0

[AntonovAnton]

Added support for compiling mathematical expression strings into executable code, producing a delegate that represents the expression.

Example:

var fn = "ln(1/x1 + √(1/(x2*x2) + 1))"
    .Compile(new { x1 = 0.0, x2 = 0.0 }, new ScientificMathContext());

var value = fn(new { x1 = -0.5, x2 = 0.5 });

This enhancement allows for efficient evaluation of complex mathematical expressions by converting them into callable delegates.

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This discussion was created from the release 2.0.0.

[ajitid]

Hello! A newbie question from me: Are there any other ways beside using new { x1 = 0.0, x2 = 0.0 } in .Compile() method? I am essentially calling the snippet you have given above in a pseudocode like this:

var expression = '0'
var fn

function callEveryFrame(newExpression, params) {
	// only compile the expression if it is out of date
	if (expression != newExpression) {
		expression = newExpression
		fn = expression.Compile(params, new MathContext());
	}

 	var value = fn(params);
	return value;
}

As you can see in my case that params in one frame can be new { a = 0, b = 0 } and in the next frame can be new { a = 0, b = 0, c = 0}. The number of parameters and their names may change over time. I couldn't pass a dictionary to .Compile() as it throws an error. Is there any other way to do this?

[ajitid]

Thank you. I want to use MathEvaluator to do calculations using DotNetStandartMathContext. Here's an example:

var dict = new Dictionary<string, double>();
dict.Add("x1", 3.0);
dict.Add("x2", 2.0);

var fn = "x1 + Math.Sin(x2) * 0.5"
    .Compile(dict, new DotNetStandartMathContext());

var value = fn(dict);
Console.WriteLine(value); // 3.4546487...

dict.Add("x1", 6.0);
dict.Add("x2", 4.0);
value = fn(dict);
Console.WriteLine(value); // 5.6215987...

// new expression:

dict.Clear();
dict.Add("x1", 3.0);
dict.Add("x3", 2.0);
dict.Add("x4", 4.0);

fn = "x1 + Math.Sin(x3) * Math.Cos(x4)"
    .Compile(dict, new DotNetStandartMathContext());

value = fn(dict);
Console.WriteLine(value); // 2.4056435...

PS: By the way, is Standard intentionally misspelt in DotNetStandartMathContext?

[AntonovAnton]

Oh, it's my mistyping I think :) I would wonder next few weeks I don't have enough time to work on the library, I can do it only in free time, I will try my best, sorry

[AntonovAnton]

Thanks for example it helps me a lot to improve the library

[AntonovAnton]

Hello @ajitid! Added in version 2.3.0

[ajitid]

Thank you!