數學表達式計算 MathParser.org-mXparser

背景

在系統中須要計算公式，參數能夠配置，相似excel的狀況，能夠實現數據的計算。

mXparser

實例

public static void main(String[] args) throws InterruptedException {
        Argument days = new Argument("days = 30");
        Expression min = new Expression("min(days/10,1)", days);
        mXparser.consolePrint(min.getExpressionString() + "----" + min.calculate());
        Expression e = new Expression("2-(32-4)/(23+4/5)-(2-4)*(4+6-98.2)+4");
        mXparser.consolePrintln("Res: " + e.getExpressionString() + " = " + e.calculate());
        Expression abs = new Expression("abs(-1)");
        mXparser.consolePrintln("Res: " + abs.getExpressionString() + " = " + abs.calculate());
        Expression sqrt = new Expression("sqrt(2)");
        mXparser.consolePrintln("Res: " + sqrt.getExpressionString() + " = " + sqrt.calculate());
        Function A = new Function("t(a,b) = 1/2 * a *b");
        Expression expression = new Expression("t(2,4)",A);
        mXparser.consolePrintln(expression.getExpressionString() +"-----------"+expression.calculate());
        Argument a = new Argument("a = 3");
        Argument b = new Argument("b = 3");
        Argument h = new Argument("h = 4");
        Expression expression1 = new Expression("t(b,h)",A,b,h,a);
        mXparser.consolePrintln(expression1.getExpressionString() +"-----------"+expression1.calculate());
        Expression expression2 = new Expression("1/2 * a *b",A,b,h,a);
        mXparser.consolePrintln(expression2.getExpressionString() +"-----------"+expression2.calculate());

    }

源碼

https://github.com/mariuszgromada/MathParser.org-mXparser