MathTest.java

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package com.graphbuilder.test;

import com.graphbuilder.math.Expression;
import com.graphbuilder.math.ExpressionTree;
import com.graphbuilder.math.FuncMap;
import com.graphbuilder.math.VarMap;

public class MathTest {

    public static void main(String[] args) {
        String s = "&pi*r^2";
        Expression x = ExpressionTree.parse(s);

        VarMap vm = new VarMap(false /* case sensitive */);
        vm.setValue("&pi", Math.PI);
        vm.setValue("r", 5);

        FuncMap fm = null; // no functions in expression

        System.out.println(x); // (pi*(r^2))
        System.out.println(x.eval(vm, fm)); // 78.53981633974483

        vm.setValue("r", 10);
        System.out.println(x.eval(vm, fm)); // 314.1592653589793
        
        x = ExpressionTree.parse("4==1");
        final double r = x.eval(vm, fm);
        System.out.println("4 == 1 --> " + r);

        x = ExpressionTree.parse("4==4");
        System.out.println("4 == 4 --> " + x.eval(vm, fm));

        x = ExpressionTree.parse("r==5");
        System.out.println("r<-10; r == 5 --> " + x.eval(vm, fm));

        x = ExpressionTree.parse("r==10");
        System.out.println("r<-10; r == 10 --> " + x.eval(vm, fm));
        
        fm = new FuncMap();
        fm.loadDefaultFunctions();
        
        x = ExpressionTree.parse("if(r==10,10.0,-10.0)");
        System.out.println("if(r==10,10.0,-10.0) --> " + x.eval(vm, fm));

        x = ExpressionTree.parse("if(r==1,10.0,-10.0)");
        System.out.println("if(r==1,10.0,-10.0) --> " + x.eval(vm, fm));
    }
}