Matrix.java ( Completed )

public class Matrix {

private int m,n;

private double[][] M;

//constructor

public Matrix(double[][] array) {

M = array;

m = array.length;

n = array[0].length;

}

//get number of columns

public int nCols() {

return n;

}

//get number of rows

public int nRows() {

return m;

}

//get ith jth entry of this matrix

public double entry(int i, int j) {

return M[i][j];

}

//compute dot product of two matrix

public Matrix dot(Matrix that) throws UndefinedMatrixOpException {

int m1 = this.nRows();

int n1 = this.nCols();

int m2 = that.nRows();

int n2 = that.nCols();

if(n1 != m2) {

throw new UndefinedMatrixOpException("Dimensions are not equal");

}

double[][] c = new double[m1][n2];

for (int i = 0; i < m1; i++)

for (int j = 0; j < n2; j++)

for (int k = 0; k < n1; k++)

c[i][j] += this.M[i][k] * that.M[k][j];

Matrix t = new Matrix(c);

return t;

}

//compute addition of two matrices

public Matrix plus(Matrix that) throws UndefinedMatrixOpException {

int m1 = this.nRows();

int n1 = this.nCols();

int m2 = that.nRows();

int n2 = that.nCols();

if(m1 != m2 || n1 != n2) {

throw new UndefinedMatrixOpException("Dimensions are not equal");

}

double[][] c = new double[m1][n1];

for (int i = 0; i < m1; i++)

for (int j = 0; j < n1; j++)

c[i][j] = this.M[i][j] + that.M[i][j];

Matrix t = new Matrix(c);

return t;

}

//return rotational matrix

public static Matrix rotationH2D(double theta) {

double[][] R = {{Math.cos(theta), -Math.sin(theta), 0},

{Math.sin(theta), Math.cos(theta), 0},

{0,0,1}};

return new Matrix(R);

}

//return translational matrix

public static Matrix translationH2D(double tx, double ty) {

double[][] R = {{1, 0 , 0},

{0, 1, 0},

{tx, ty, 1}};

return new Matrix(R);

}

//return scaling matrix

public static Matrix vectorH2D(double x, double y) {

double[][] R = {{x, 0 , 0},

{0, y, 0},

{0, 0, 1}};

return new Matrix(R);

}

//return identity matrix

public static Matrix identity(int n) {

double[][] R = new double[n][n];

for (int i = 0; i < n; i++)

R[i][i] = 1;

return new Matrix(R);

}

public String toString() {

StringBuilder sb = new StringBuilder();

for (int i = 0; i < m; i++) {

for (int j = 0; j < n; j++) {

sb.append(M[i][j]);

sb.append('\t');

}

sb.append(' ');

}

return sb.toString();

}

}

Orbit.pde (Not complete) - Has to follow instructions in the code

import java.util.*; import java.awt.*;

Orbiter sun; // The root orbiter int lastMillis; double[][] originM = {{0},{0},{1}}; Matrix origin = new Matrix(originM);

// A few fun parameters boolean clearBackground = true; double speedModifier = 1.0; // Set in some of the scenes to change the speed.

// One default scene (selected in the setup() function void setupScene1() { sun = new Orbiter(null, 0, 0, 0, Orbiter.Type.CIRCLE, Color.yellow); Orbiter earth = new Orbiter(sun, 50, 0, 1, Orbiter.Type.CIRCLE, Color.blue); Orbiter moon = new Orbiter(earth, 30, 0, 1, Orbiter.Type.CIRCLE, Color.gray); Orbiter moonSatellite = new Orbiter(moon, 20, 0, 1, Orbiter.Type.CIRCLE, Color.gray); Orbiter jupiter = new Orbiter(sun, 200, 0, 0.5, Orbiter.Type.CIRCLE, Color.red); Orbiter jupiterMoon = new Orbiter(jupiter, 75, 0, 2, Orbiter.Type.CIRCLE, Color.green); Orbiter jupiterExplorer = new Orbiter(jupiterMoon, 40, 0, -1, Orbiter.Type.SQUARE, Color.orange); Orbiter jupiterExplorerRobot = new Orbiter(jupiterExplorer, 20, 0, -3, Orbiter.Type.TRIANGLE, Color.magenta); } // A second default scene void setupScene2() { speedModifier = 0.25; sun = new Orbiter(null, 0, 0, 0, Orbiter.Type.TRIANGLE, Color.yellow); Orbiter earth = new Orbiter(sun, 50, 0, 10, Orbiter.Type.TRIANGLE, Color.blue); Orbiter moon = new Orbiter(earth, 30, 0, 20, Orbiter.Type.TRIANGLE, Color.gray); Orbiter moonSatellite = new Orbiter(moon, 20, 0, 30, Orbiter.Type.TRIANGLE, Color.gray); Orbiter jupiter = new Orbiter(sun, 200, 0, 5, Orbiter.Type.TRIANGLE, Color.red); Orbiter jupiterMoon = new Orbiter(jupiter, 75, 0, 2, Orbiter.Type.TRIANGLE, Color.green); Orbiter jupiterExplorer = new Orbiter(jupiterMoon, 40, 0, 8, Orbiter.Type.TRIANGLE, Color.orange); Orbiter jupiterExplorerRobot = new Orbiter(jupiterExplorer, 20, 0, -6, Orbiter.Type.TRIANGLE, Color.magenta); }

// The setup. You don't need to edit this other than to switch scenes by commenting out // the setupScene1() and uncommenting setupScene2(). void setup() { size(800, 800); background(0); setupScene1(); //setupScene2(); // Run this one with clearBackground set to false lastMillis = millis(); }

// The draw function // DO NOT EDIT void draw() { if (clearBackground) background(0); // Make the background black. int currentMillis = millis(); // Get the current number of milliseconds int elapsedMillis = currentMillis - lastMillis; // Get the number of milliseconds elapsed since last call double timeDelta = elapsedMillis / 1000.0; updateOrbiters(timeDelta * speedModifier); pushMatrix(); scale(1, -1); translate(width / 2, - height / 2); drawOrbiters(); popMatrix(); lastMillis = currentMillis; }

void updateOrbiters(double timeDelta) { // TODO // This code should traverse the orbiters (in BFS or DFS, but I used BFS) // order using a stack or a queue (your choice), and call updateRotation // on each one using the timeDelta parameter. // // Recall that Java has a Queue data type and a Stack interface }

void drawOrbiters() { // TODO // This code should traverse the orbiters (in BFS or DFS order, i used BFS) // and call drawOrbiter on each orbiter. }

// The code for drawing an orbiter. This is called from your drawOrbiters() method // but you should not have to edit it. void drawOrbiter(Orbiter orbiter) { try { Matrix position = orbiter.getMatrix().dot(origin); int px = (int) Math.round(position.entry(0,0) / position.entry(2,0)); int py = (int) Math.round(position.entry(1,0) / position.entry(2,0)); // Draw the orbiter noStroke(); fill(orbiter.getFillColor().getRed(), orbiter.getFillColor().getGreen(), orbiter.getFillColor().getBlue()); switch (orbiter.getType()) { case CIRCLE: ellipse(px, py, 16, 16); break; case SQUARE: rect(px-4, py-4, 8, 8); break; case TRIANGLE: triangle(px, py+3, px-2, py-1, px+2, py-1); break; } noFill(); // Draw the orbit path if (clearBackground) { stroke(60); for (Orbiter child : orbiter.getChildren()) { int radius = (int) (2*child.getOrbitRadius()); ellipse(px, py, radius, radius); } } } catch (UndefinedMatrixOpException umoe) { } }

Orbiter.java (Not complete) - Has to follow instructions in the code

import java.awt.Color;

import java.util.*;

/**

* An Orbiter is an object that orbits some other object, called its

parent.

* The center of an orbital system is an Orbiter with no parent.

* Each Orbiter may have child Oribters that orbit it.

*

* An Orbiter stores its orbital radius and current orbit angle.

*/

public class Orbiter {

public enum Type {

CIRCLE, SQUARE, TRIANGLE

}

private final double orbitRadius;

private final Type type;

private final Color fillColor;

private double orbitAngle;

private double orbitSpeed;

private final List children = new LinkedList();

private final Orbiter parent;

public Orbiter(Orbiter parent, double orbitRadius, double orbitAngle,

double orbitSpeed, Type type, Color fillColor) {

this.orbitRadius = orbitRadius;

this.orbitAngle = orbitAngle;

this.type = type;

this.fillColor = fillColor;

this.parent = parent;

this.orbitSpeed = orbitSpeed;

if (parent != null) parent.children.add(this);

}

public double getOrbitRadius() { return orbitRadius; }

public double getOrbitAngle() { return orbitAngle; }

public Color getFillColor() { return fillColor; }

public Type getType() { return type; }

public Orbiter getParent() { return parent; }

public List getChildren() { return children; }

/**

* Updates the rotation of this orbiter by the amount specified in the

deltaAngle parameter.

* @param deltaAngle The amount of rotation angle to add the to the

current rotation.

*/

public void updateRotation(double timeDelta) {

orbitAngle += (timeDelta * orbitSpeed);

}

public Matrix getMatrix() throws UndefinedMatrixOpException {

// TODO

// If this is the root node, then return the 3x3 identity matrix

// If this is not the root node, should return the transformation

// matrix for this orbiter (see the writeup for an idea of how to

// do this). Make sure you've coded the Matrix class first.