Thread: Problem with method

public abstract class SimplePolygon {
 
  public abstract Vertex2D getVertex(int index) throws IllegalArgumentException;
  public abstract int getNumVertices();
 
  public double getArea() {
 
    int area = 0;
 
    for (int i = 0; i < getNumVertices(); i++) {
 
      area += (getVertex(i).getX() * getVertex(i + 1).getY() - getVertex(i + 1).getX() * getVertex(i).getY() );
    }
 
    return 0.5 * area;
  }
 
  public double getWidth() {
 
    double max = -Double.MAX_VALUE,
           min = Double.MAX_VALUE;
 
    for (int i = 0; i < getNumVertices(); i++) {
 
      max = Math.max(max, getVertex(i).getX() );
      min = Math.min(min, getVertex(i).getX() );
    }
 
    return max - min;
  }
 
  public double getHeight() {
 
    double max = -Double.MAX_VALUE,
           min = Double.MAX_VALUE;
 
    for (int i = 0; i < getNumVertices(); i++) {
 
      max = Math.max(max, getVertex(i).getY() );
      min = Math.min(min, getVertex(i).getY() );
    }
 
    return max - min;
  }
 
  public double getLength() {
 
    double length = 0;
 
    for (int i = 0; i < getNumVertices(); i++) {
 
      length += getVertex(i).distance(getVertex(i + 1));
    }
 
    return length;
  }
 
  public String toString() {
 
    StringBuilder result = new StringBuilder();
 
    for (int i = 0; i < getNumVertices(); i++) {
 
      result.append(" "+ getVertex(i).toString());
    }
 
    return "Polygon: vertices ="+ result;
  }
}
 
public class ArrayPolygon extends SimplePolygon {
 
  private Vertex2D[] vertices;
 
  public ArrayPolygon(Vertex2D[] vertices) {
 
    if (vertices == null) throw new IllegalArgumentException();
 
    for (int i = 0; i < vertices.length; i++) {
 
      if (vertices[i] == null) throw new NullPointerException();
    }
 
    this.vertices = new Vertex2D[vertices.length];
 
    System.arraycopy(vertices, 0, this.vertices, 0, vertices.length);
  }
 
  public Vertex2D getVertex(int index) throws IllegalArgumentException {
 
    if (index < 0) throw new IllegalArgumentException();
 
    return vertices[index % vertices.length];
  }
 
  public int getNumVertices() {
 
    return vertices.length;
  }
 
  public ArrayPolygon invert() {
 
    Vertex2D[] temp = new Vertex2D[vertices.length];
 
    for (int i = vertices.length - 1, y = 0; i >= 0; i--) {
 
      temp[++y] = vertices[i];
    }
 
    return new ArrayPolygon(temp);
  }
 
  public boolean compare(ArrayPolygon pol) {
 
    int i = 0;
 
    for (; i < vertices.length; i++) {
 
      if (vertices[0].equals(pol.getVertex(i) ) ) break;
    }
 
    System.out.println(i +"; "+ vertices.length);
    return true;
  }
}
 
public class Vertex2D {
 
  private double x,y;
 
  public Vertex2D(double newX, double newY) {
 
    x = newX;
    y = newY;
  }
 
  public double getX() {
 
    return x;
  }
 
  public double getY() {
 
    return y;
  }
 
  public String toString() {
 
    return "["+ x +", "+ y +"]";
  }
 
  public double distance (Vertex2D vert) {
 
    if(vert == null) {
 
      return -1.0;
    }
    else {
 
      return Math.sqrt( (vert.x - x) * (vert.x - x) 
                      + (vert.y - y) * (vert.y - y) );
    }
 
  }
 
}
 
public class Tester {
 
  public static void main(String[] args) {
 
    Vertex2D[] vert1 = {
        new Vertex2D(-100,-100),
        new Vertex2D( -40,  10),
        new Vertex2D(  50,  20),
        new Vertex2D(  10, -20),
        new Vertex2D(  60, -40)
    };
 
    Vertex2D[] vert2 = {
        new Vertex2D(  50,  20),
        new Vertex2D(  10, -20),
        new Vertex2D(  60, -40),
        new Vertex2D(-100,-100),
        new Vertex2D( -40,  10)
    };
 
    Vertex2D[] vert3 = {
        new Vertex2D( -40,  10),
        new Vertex2D(-100,-100),
        new Vertex2D(  60, -40),
        new Vertex2D(  10, -20),
        new Vertex2D(  50,  20)
    };
 
    Vertex2D[] vert4 = {
        new Vertex2D( -40,  10),
        new Vertex2D(-100,-100),
        new Vertex2D(  50,  20),
        new Vertex2D(  10, -20),
        new Vertex2D(  60, -40)
    };
 
    System.out.println(new ArrayPolygon(vert1).compare(new ArrayPolygon(vert1)));
    System.out.println("");
    System.out.println(new ArrayPolygon(vert1).compare(new ArrayPolygon(vert2)));
    System.out.println("");
    System.out.println(new ArrayPolygon(vert1).compare(new ArrayPolygon(vert3)));
    System.out.println("");
    System.out.println(new ArrayPolygon(vert1).compare(new ArrayPolygon(vert4)));
  }
}

I think when I run Tester.java it have to return something like 0; 5 \n true \n \n 3; 5 \n true \n \n 2; 5 \n true \n \n 2;5 \n true. But it is returning 0; 5 \n true \n \n 5; 5 \n true \n \n 5; 5 \n true \n \n 5;5 \n true. Whats wrong with my code? I am looking at it for a while and I can't come up to whats wrong. It's one file for each class.

basically I am comparing two instances of class Vertex 2D.

int i = 0;
 
for (; i < vertices.length; i++) {
 
  if (vertices[0].equals(pol.getVertex(i) ) ) break;
}
 
System.out.println(i +"; "+ vertices.length);

so I take zero Vertex2D from vert1 and then I am searching for first match in vertex1, vertex2, vertex3 then vertex4 and that matches are 0 3 1 1 so I think output was to be 0 3 1 1 or 1 4 2 2 but real output is 0 5 5 5 and thats a problem and I don't know why it is not working. :-(

 Vertex2D[] vert1 = {
        new Vertex2D(-100,-100),
        new Vertex2D( -40,  10),
        new Vertex2D(  50,  20),
        new Vertex2D(  10, -20),
        new Vertex2D(  60, -40)
    };
 
    Vertex2D[] vert2 = {
        new Vertex2D(  50,  20),
        new Vertex2D(  10, -20),
        new Vertex2D(  60, -40),
        new Vertex2D(-100,-100),
        new Vertex2D( -40,  10)
    };
 
    Vertex2D[] vert3 = {
        new Vertex2D( -40,  10),
        new Vertex2D(-100,-100),
        new Vertex2D(  60, -40),
        new Vertex2D(  10, -20),
        new Vertex2D(  50,  20)
    };
 
    Vertex2D[] vert4 = {
        new Vertex2D( -40,  10),
        new Vertex2D(-100,-100),
        new Vertex2D(  50,  20),
        new Vertex2D(  10, -20),
        new Vertex2D(  60, -40)
    };

Sorry for duplicate I don't know how to delete it.

Try to add this

System.out.println(vertices[0] +"; "+ pol.getVertex(i));

before

if (vertices[0].equals(pol.getVertex(i) ) ) break;

and you will see it have to break that shitty for but it doesn't I just don't get it why.

So that if have to break for if there are same values as you can see in first one it's all ok but in another ones it just failed I don't know why.

[-100.0, -100.0]; [-100.0, -100.0]
0; 5
true
 
[-100.0, -100.0]; [50.0, 20.0]
[-100.0, -100.0]; [10.0, -20.0]
[-100.0, -100.0]; [60.0, -40.0]
[-100.0, -100.0]; [-100.0, -100.0]
[-100.0, -100.0]; [-40.0, 10.0]
5; 5
true
 
[-100.0, -100.0]; [-40.0, 10.0]
[-100.0, -100.0]; [-100.0, -100.0]
[-100.0, -100.0]; [60.0, -40.0]
[-100.0, -100.0]; [10.0, -20.0]
[-100.0, -100.0]; [50.0, 20.0]
5; 5
true
 
[-100.0, -100.0]; [-40.0, 10.0]
[-100.0, -100.0]; [-100.0, -100.0]
[-100.0, -100.0]; [50.0, 20.0]
[-100.0, -100.0]; [10.0, -20.0]
[-100.0, -100.0]; [60.0, -40.0]
5; 5
true

and what I want is

[-100.0, -100.0]; [-100.0, -100.0]
0; 5
true
 
[-100.0, -100.0]; [50.0, 20.0]
[-100.0, -100.0]; [10.0, -20.0]
[-100.0, -100.0]; [60.0, -40.0]
[-100.0, -100.0]; [-100.0, -100.0]
3; 5
true
 
[-100.0, -100.0]; [-40.0, 10.0]
[-100.0, -100.0]; [-100.0, -100.0]
1; 5
true
 
[-100.0, -100.0]; [-40.0, 10.0]
[-100.0, -100.0]; [-100.0, -100.0]
1; 5
true

--- Update ---

So problem was Vertex2D is my own class and I have to do my own equals for comparing this classes.