Java复数，3类

Question

我将重复我在java中必须做的事情，以我认为我需要思考的方式来完成这项任务。(对不起，我是编程新手)。

第一类；为复数定义类。我发现这相当简单，我的答案如下。

public class Complex {
    private double real;
    private double imaginary;

    public Complex()
    {
        this( 0.0, 0.0 );
    }

    public Complex( double r, double i )
    {
        real = r;
        imaginary = i;
    } 
}

第二类；使用公共静态方法进行加法和减法，从第一类中调用实数和虚数。这一部分我发现更具挑战性，因为我没有100%掌握这一点。

Public class ComplexArith
public static ComplexAdd(Complex one, Complex two)
return Complex(one.getReal() + two.getReal(), one.getImaginary() + two.getImaginary());

public static ComplexSub(Complex one, Complex two)
return Complex(one.getReal() - two.getReal(), one.getImaginary - two.getImaginary());

第三部分是要求用户输入，并对复数集进行加减。我对此并不熟悉，因为我从来没有要求用户输入(0.0,0.0)格式。

对整个代码有什么见解吗？我是在正确的轨道上吗？

编辑：

我第一次上完课的时候。感谢你们。

第二节课，我遇到了编译问题，因为我不能完全理解一些东西。

public class ComplexArith{
public static Complex add(Complex one, Complex two)
{
return Complex(one.getReal() + two.getReal(), one.getImaginary() + two.getImaginary());
}
public static Complex sub(Complex one, Complex two)
{
return Complex(one.getReal() - two.getReal(), one.getImaginary - two.getImaginary());
}
}

我知道需要定义一和二，但我不知道如何定义它们。我该如何定义它们呢？我以为它是从双r，双i的Complex类中调用的。

我还认为在第一个类中也定义了.getImaginary。这是第一个类。

public class Complex
{
private double real;
private double imaginary;

public Complex()
{
    this( 0.0, 0.0 );
}


public Complex( double r, double i )
{
    real = r;
    imaginary = i;
}

public double getReal() {
  return this.real;
}

public double getImaginary() {
  return this.imaginary;
}
}

Answer 1

这是正确的，但是您需要在Complex对象上使用getters。

例如：

   public class Complex
{
    private double real;
    private double imaginary;

    public Complex()
    {
        this( 0.0, 0.0 );
    }


    public Complex( double r, double i )
    {
        real = r;
        imaginary = i;
    }

    public double getReal() {
      return this.real;
    }

    public double getImaginary() {
      return this.imaginary;
    }
}

您的方法还需要返回类型：

public class ComplexArith
{   
    public static Complex complexAdd(Complex one, Complex two) {
        return Complex(one.getReal() + two.getReal(),
                      one.getImaginary() + two.getImaginary());
    }

    public static Complex complexSub(Complex one, Complex two) {
        return Complex(one.getReal() - two.getReal(),
                       one.getImaginary - two.getImaginary());
    }
}

此外，这与您的程序的功能无关，但习惯上是让您的方法使用camelCase。因此，您的方法应该如下所示：

public static Complex complexAdd(Complex one, Complex two) {
    return Complex(one.getReal() + two.getReal(), 
                  one.getImaginary() + two.getImaginary());
}

Answer 2

就我个人而言，我会把这些算术运算放在复杂的类中。这些都是真正的复数运算，所以我不会把它们封装在复杂类之外。

我会考虑让复数变得不可变。这样就是线程安全的。

我喜欢静态的add，sub，mul，div方法。确保它们返回一个Complex (现在不返回)。其他方法，如余弦、正弦等，可能属于复杂包中的Math类。有关实数的示例，请参阅java.lang.Math。

您需要返回"new Complex“。你写的代码不能编译。

Answer 3

这是我的实现，我在一个类上做了所有的事情：

package name.puzio.math;

public final class ComplexNumber {
private final double imaginary;
private final double real;

@Override
public final boolean equals(Object object) {
    if (!(object instanceof ComplexNumber))
        return false;
    ComplexNumber a = (ComplexNumber) object;
    return (real == a.real) && (imaginary == a.imaginary);
}

public ComplexNumber(double real, double imaginary) {
    this.imaginary = imaginary;
    this.real = real;
}

public static final ComplexNumber createPolar(double amount, double angel) {
    return new ComplexNumber(amount * Math.cos(angel), amount * Math.sin(angel));
}

public final double getImaginary() {
    return imaginary;
}

public final double getReal() {
    return real;
}

public final double getAmount() {
    return Math.sqrt((real * real) + (imaginary * imaginary));
}

public final double getAngle() {
    return Math.atan2(imaginary, real);
}

public final ComplexNumber add(ComplexNumber b) {
    return add(this, b);
}

public final ComplexNumber sub(ComplexNumber b) {
    return sub(this, b);
}

public final ComplexNumber div(ComplexNumber b) {
    return div(this, b);
}

public final ComplexNumber mul(ComplexNumber b) {
    return mul(this, b);
}

public final ComplexNumber conjugation() {
    return conjugation(this);
}

/**
 * Addition:
 * @param a
 * @param b
 * @return
 */
private final static ComplexNumber add(ComplexNumber a, ComplexNumber b) {
    return new ComplexNumber(a.real + b.real, a.imaginary + b.imaginary);
}

/**
 * Subtraktion:
 * @param a
 * @param b
 * @return
 */
private final static ComplexNumber sub(ComplexNumber a, ComplexNumber b) {
    return new ComplexNumber(a.real - b.real, a.imaginary - b.imaginary);
}

/**
 * Multiplikation:
 * @param a
 * @param b
 * @return
 **/
private final static ComplexNumber mul(ComplexNumber a, ComplexNumber b) {
    return new ComplexNumber((a.real * b.real) - (a.imaginary * b.imaginary), (a.imaginary * b.real) + (a.real * b.imaginary));
}

/**
 * Division:
 * @param a
 * @param b
 * @return
 **/
private final static ComplexNumber div(ComplexNumber a, ComplexNumber b) {
    double d = (b.real * b.real) + (b.imaginary * b.imaginary);
    if (d == 0)
        return new ComplexNumber(Double.NaN, Double.NaN);
    return new ComplexNumber(((a.real * b.real) + (a.imaginary * b.imaginary)) / d, ((a.imaginary * b.real) - (a.real * b.imaginary)) / d);
}

/**
 * Konjugation:
 * @param a
 * @return
 **/

private final static ComplexNumber conjugation(ComplexNumber a) {
    return new ComplexNumber(a.real, -a.imaginary);
}
}