Question

For this task you will create a Point3D class to represent a point that has coordinates in three dimensions labeled x, y and z. You will then use the class to perform some calculations on an array of these points. You need to draw a UML diagram for the class (Point3D) and then implement the class.
The Point3D class will have the following state and functionality:

• Three data fields, x, y and z, of type double, represent the point’s coordinates
• Additional data field, colour, of type String, represents the point's color
• A no-arg constructor creates a point at position (0, 0, 0) and "Red" colour.
• Another constructor creates a point with specified coordinates and colour.
• A getter method is provided for each of the fields.
• An accessor method named distance returns the distance between the current point and another point passed as an argument.
• The distance method is overloaded to accept the coordinates of the other point.

Write a TestPoint3D class that will have a main method, and perhaps other methods as required by good design, to test your Point3D class. It will not have user input because this class will stand as a record of the tests you have applied and you will be able to run it whenever you alter your Point3D class. For the TestPoint3D class you will need to do the following:

• Test the basic state and functionality of the Point3D class. Each of the constructors and each of the methods should be tested using some different data values. The test code should display values so that they can be checked.
• Write some code to create an array of at least 10 Point3D objects.
• Write a method max, which will accept the array of points as an argument, and will calculate and display the maximum distance between the points in the array, and the pair of points for which the maximum occurs.
• Write a method min, which will accept the array of points as an argument, and will calculate and display the minimum distance between the points in the array, and the pair of points for which the minimum occurs.

Answer 1

//Point3D.java

public class Point3D {

      

// instance variables

       private double x;

       private double y;

       private double z;

       private String colour;

      

       // constructors

       public Point3D()

       {

             x = 0;

             y = 0;

             z = 0;

             colour = "Red";

       }

      

       public Point3D(double x, double y, double z, String colour)

       {

             this.x = x;

             this.y = y;

             this.z = z;

             this.colour = colour;

       }

      

// getters

       public double getX()

       {

             return x;

       }

      

       public double getY()

       {

             return y;

       }

      

       public double getZ()

       {

             return z;

       }

      

       public String getColour()

       {

             return colour;

       }

      

       // distance methods

       public double distance(Point3D point)

       {

             return(Math.sqrt(Math.pow(x-point.x,2)+Math.pow(y-point.y, 2)+Math.pow(z-point.z, 2)));

       }

       public double distance(double x, double y, double z)

       {

             return(Math.sqrt(Math.pow(this.x-x,2)+Math.pow(this.y-y, 2)+Math.pow(this.z-z, 2)));

       }

      

}

//end of Point3D.java

//TestPoint3D.java

public class TestPoint3D {

      

       /* method that calculates and displays the maximum distance between two points in the given arrays and the points with the maximum distance*/

       public static void max(Point3D points[])

       {

             double maxDist = 0;

             Point3D point1 =null, point2= null;

            

             for(int i=0;i<points.length;i++)

             {

                    for(int j=i+1;j<points.length;j++)

                    {

                           double dist = points[i].distance(points[j]);

                           if( dist > maxDist)

                           {

                                 point1 = points[i];

                                 point2 = points[j];

                                 maxDist = dist;

                           }

                    }

             }

            

             if(point1 != null && point2 != null)

             {

                    System.out.println("Maximum distance : "+maxDist+" between points ("+point1.getX()+", "+point1.getY()+", "+point1.getZ()+") and "

                                 +" ("+point2.getX()+", "+point2.getY()+", "+point2.getZ()+")");

             }

       }

      

       /* method that calculates and displays the minimum distance between two points in the given arrays and the points with the minimum distance*/

       public static void min(Point3D points[])

       {

             double minDist = Double.MAX_VALUE;

             Point3D point1 =null, point2= null;

            

             for(int i=0;i<points.length;i++)

             {

                    for(int j=i+1;j<points.length;j++)

                    {

                           double dist = points[i].distance(points[j]);

                           if( dist < minDist)

                           {

                                 point1 = points[i];

                                 point2 = points[j];

                                 minDist = dist;

                           }

                    }

             }

            

             if(point1 != null && point2 != null)

             {

                    System.out.println("Minimum distance : "+minDist+" between points ("+point1.getX()+", "+point1.getY()+", "+point1.getZ()+") and "

                                 +" ("+point2.getX()+", "+point2.getY()+", "+point2.getZ()+")");

             }

       }

      

       public static void main(String[] args) {

             Point3D point1 = new Point3D();

             Point3D point2 = new Point3D(2,3,1,"Yellow");

            

             System.out.println("Point1 : ("+point1.getX()+","+point1.getY()+","+point1.getZ()+") Color : "+point1.getColour());

             System.out.println("Point2 : ("+point2.getX()+","+point2.getY()+","+point2.getZ()+") Color : "+point2.getColour());

            

             Point3D points[] = {new Point3D(),new Point3D(1,2,3,"Red"),new Point3D(5,1,3,"Yellow"),new Point3D(8.5,1.24,4,"Blue"),new Point3D(1.5,2,7.5,"Green")

                           ,new Point3D(12,5.5,8,"Magenta"),new Point3D(8,2.4,3.25,"Cyan"),new Point3D(9,12,8,"Purple"),new Point3D(8,0.5,12,"Pink"),new Point3D(0,13.6,7.5,"Orange")};

             max(points);

             min(points);

            

       }

}

//end of TestPoint3D.java

Output: