Mathie

Description

Mathie is a mathematical expression framework. It creates expression graphs (http://gerritdrost.com/2013/09/mathematical-expression-graphs) and provides an easy way to interface with them. With Mathie you can set up a framework of expressions sharing variables and quickly re-evaluate your expressions when the variables change.

Little boilerplate code!

Using annotations and some injection code, Mathie makes it possible to use expressions in a class without writing lots of boilerplate code.

Quick

Mathie's focus is quick (re-)evaluation, not fast parsing(although that's still pretty quick as well).

Extendable

Missing a function/operator? Create an issue if you think it should be included by default or easily extend Mathie if it's a project specific operator!

Using Mathie

Maven

<dependency>
    <groupId>com.gerritdrost.libs.mathie</groupId>
    <artifactId>mathie</artifactId>
	<version>0.0.1</version>
</dependency>

Examples

More solid documentation is to follow soon. For now, here are some examples:

Using annotations

public class MathieTest implements Injectable {

	@Env
	private ExpressionEnvironment env;

	@Expr("16/x")
	private Expression exp1;

	@Var(name = "x", val = 2.0)
	private Variable x;

	public MathieTest() {
		// you could even integrate this little chunk of code into a superclass, but then you can't extend any other
		// classes.
		Injector.inject(this);
	}

	@Override
	public void injectionDone() {
		// x = 2 since we set it to be that, so 16/2 = 8.
		System.out.println(exp1);
		x.set(8.0);
		// 16.0/8.0 obviously is 2.0
		System.out.println(exp1);
	}
}

Bare java

public class MathieTest {

	public MathieTest() {
		ExpressionEnvironment t = new ExpressionEnvironment();

		Expression e = t.getExpression("2*x");

		// when variables are initialized, they are set to 1.0
		System.out.println(e);

		// let's get that variable object
		Variable x = t.getVariable("x");
		x.set(5.0);

		// Re-evaluation is done automagically
		System.out.println(e);
	}
}

Supported operators/functions

These operators and functions are currently supported. More are being implemented.

'+' - Addition
'-' - Subtraction
'*' - Multiplication
'/' - Division
'^' - Exponentiation
abs(a) - Absolute value
sin(a) - Sine
cos(a) - Cosine
tan(a) - Tangent
sec(a) - Secant
csc(a) - Cosecant
cot(a) - Cotangent
min(a,b,c,...) - Returns the lowest value of at least 2 parameters
max(a,b,c,...) - Returns the highest value of at least 2 parameters
equals(a,b,c,...) - Returns 1.0 if all parameters are equal, returns 0.0 otherwise.

License

Mathie is provided under the MIT license. More info:

gerritdrost / mathie