complex.java

此源码是对复数进行计算的,包括复数的加减乘除.方法简单,容易理解.

public class Complex
{
    double real,img;    //实部和虚部
    
    public Complex()        //默认构造方法
    {
        this.real=0;
        this.img =0;
    }
    public Complex(double real,double img)    //带参数的构造方法
    {
        this.real=real;
        this.img =img;
    }
    public double getReal()
     { return this.real;    }        //得到实部

    public double getImage() 
     { return this.img;    }        //得到虚部

    public double getReal(Complex c) 
     {    return c.real;        }   //得到复数c的实部，这两个函数看起来好像有点多余，但在特殊的情况下会有用

    public double getImage(Complex c) 
     {    return c.img;            }        //得到复数c的虚部

    public void setReal    (double real) 
     {    this.real=real;        }        //设置实部

    public void setImage(double img) 
     {    this.img =img;        }        //设置虚部

    public Complex addComplex(Complex a,Complex b)    //两个复数相加，结果返回
    {
        Complex temp =new Complex();
        temp.real=a.real+b.real;
        temp.img =a.img +b.img;
        return temp;
    }    
    public Complex decComplex(Complex a,Complex b)    //两个复数相减，结果返回
    {
        Complex temp = new Complex();
        temp.real = a.real - b.real;
        temp.img  = a.img  - b.img;
        return temp;
    }
    public Complex mulComplex(Complex a,Complex b)    //两个复数相乘，结果返回
    {
        Complex temp = new Complex();
        temp.real = a.real*b.real-a.img*b.img;
        temp.img    = a.real*b.img+a.img*b.real;
        return temp;
    }
    public Complex divComplex(Complex a,Complex b)    //两个复数相除，结果返回
    {
        Complex temp = new Complex();
        temp.real=(a.real*b.real+a.img*b.img)/(b.real*b.real+b.img*b.img);
        temp.img =(a.img*b.real-a.real*b.img)/(b.real*b.real+b.img*b.img);
        return temp;
    }
    
    public void addComplex(Complex cplx)                //加上一个复数
    {
        this.real=this.real+cplx.real;
        this.img =this.img +cplx.img;
    }
    public void decComplex(Complex cplx)                //减去一个复数
    {
        this.real=this.real-cplx.real;
        this.img =this.img -cplx.img;
    }
    public void mulComplex(Complex cplx)                //乘与一个复数
    {
        double temp=this.real;    //下一行代码会改变this.real的值，先用一个临时变量存起来
        this.real=this.real*cplx.real-this.img*cplx.img;
        this.img =temp*cplx.img+this.img*cplx.real;
    }
    public void divComplex(Complex cplx)                //除去一个复数
    {
        double temp=this.real;    //下一行代码会改变this.real的值，先用一个临时变量存起来
        this.real=(this.real*cplx.real+this.img*cplx.img)/(cplx.real*cplx.real+cplx.img*cplx.img);
        this.img =(this.img*cplx.real-temp*cplx.img)/(cplx.real*cplx.real+cplx.img*cplx.img);
    }

    /** *//****以上是这个复数类的所有函数，下面是一些测试的代码****/

    public void printComplex()        //在console端输出这个复数,测试用
    {        
        System.out.println(""+this.real+"+"+this.img+"i");//这里可以填加一点代码以判断虚部的正负，这个工作我没有做
    }
    
    public static void main(String[] args)        //测试代码
    {
        Complex cc=new Complex(4,8);
        cc.printComplex();
        Complex dd=new Complex(2,2);
        dd.printComplex();
        System.out.println("-----------------");
        Complex ff=new Complex();
        
        ff=ff.addComplex(cc,dd);
        ff.printComplex();
        ff=ff.decComplex(cc,dd);
        ff.printComplex();
        ff=ff.mulComplex(cc,dd);
        ff.printComplex();
        ff=ff.divComplex(cc,dd);
        ff.printComplex();
        System.out.println("-----------------");
         cc.addComplex(dd);
        cc.printComplex();        
        cc=new Complex(4,8);
        cc.decComplex(dd);
        cc.printComplex();
        cc=new Complex(4,8);
        cc.mulComplex(dd);
        cc.printComplex();
        cc=new Complex(4,8);
        cc.divComplex(dd);
        cc.printComplex();
        System.out.println("-----------------");
        cc.setReal(123);
        cc.setImage(456);
        cc.printComplex();
        System.out.println(""+cc.getReal()+"+"+cc.getImage()+"i");    
        System.out.println("-----------------");
    }
}