舍入浮点数

我正在尝试创建一个专门用于浮点精度管理的类。

实际上,它需要你的双精度和小数位数,然后每次你都要用 set(double) ,数字将自动舍入。

public class Precision {

    public Precision(int rounding, double n)    {
        setRounding(rounding);
        set(n);
    }

    public double get() {
        return this.n;
    }

    public void set(double n)   {
        this.n = Math.round(n * Math.pow(10, rounding)) / rounding;
    }

    public void inc(double n)   {
        set(get() + n);
    }

    public int getRounding()    {
        return this.rounding;
    }

    public void setRounding(int rounding)   {
        if (rounding > 324)
            throw new UnsupportedOperationException("Can't round numbers after 324 decimals");
        else
            this.rounding = rounding;
    }

    public void copy(Precision p)   {
        this.rounding = p.getRounding();
        this.n = p.n;
    }

    private int rounding;
    private double n;
}

但它并没有像预期的那样工作,当我对数字进行运算时,它根本没有设置预期的数字。例如:

Precision p = new Precision(2, 0);
// Here p.n is worth 0.00
p.set(8.6596)
// Here p.n is worth 432.5
p.inc(3.2);
// Here p.n is worth 21785