Programming Resources For Fun and Learning

# FunctionGrowth

GraphPanel.java

```import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.*;
import java.applet.*;
import javax.swing.*;
/**
* A panel that draws a number of graphs.
* @author Cory Lueninghoener
*/

public class GraphPanel extends JPanel {
// When adding functions, use the same numbers as their order in the combobox
public static final int
ONE = 0,
N_POINT_ONE = 1,
LOG_N = 2,
SQRT_N = 3,
N = 4,
N_LOG_N = 5,
N_SQUARED = 6,
N_CUBED = 7,
N_FOURTH = 8,
TWO_POW_N = 9,
THREE_POW_N = 10,
N_FACTORIAL = 11;

//public static final int ONE = 0, N = 1, N_SQUARED = 2, N_CUBED = 3, LOG_N = 4, N_LOG_N = 5, TWO_POW_N = 6, N_FACTORIAL = 7;

private int curGraph1 = ONE;
private int curGraph2 = N;
private int curGraph3 = N_SQUARED;
private int const1 = 1;
private int const2 = 1;
private int const3 = 1;
private int xMax = 5;
private int yMax = 5;
private int xVal = 5;
private int yVal = 5;

/**
* Creates a new GraphPanel object
*/
public GraphPanel() {
System.out.println("Creating GraphPanel");
try {
jbInit();
}
catch(Exception e) {
//e.printStackTrace();
}

}

/**
* Sets the constant multiplier for a graph
* @param graph Specifies which graph to set constant for
* @param constant The new constant value
*/
public void setCurConst(int graph, int constant){
switch(graph){
case 1:
const1 = constant;
break;
case 2:
const2 = constant;
break;
case 3:
const3 = constant;
break;
}
}

/**
* Gets the current constant multiplier for a graph
* @param graph Specifies which graph you want to know about
* @return The current constant value
*/
public int getCurConst(int graph){
switch(graph){
case 1:
return const1;
case 2:
return const2;
case 3:
return const3;
}
return 0;
}

/**
* Sets the current function a particular graph should display
* @param graph Specifies which graph to change
* @param function Specifies which function the graph should display
*/
public void setCurGraph(int graph, int function){
switch(graph){
case 1:
curGraph1 = function;
break;
case 2:
curGraph2 = function;
break;
case 3:
curGraph3 = function;
break;
}
}

/**
* Gets the function currently being displayed by a graph
* @param graph Specifies which graph you want to know about
* @return The current function being displayed by the specified graph
*/
public int getCurGraph(int graph){
switch(graph){
case 1:
return curGraph1;
case 2:
return curGraph2;
case 3:
return curGraph3;
}
return 0;
}

public void setXVal(int n){
xVal = n;
}

public void setYVal(int n){
yVal = n;
}

public int getXVal(){
return xVal;
}

public int getYVal(){
return yVal;
}

public void setXMax(int n){
xMax = n;
}

public void setYMax(int n){
yMax = n;
}

public int getXMax(){
return xMax;
}

public int getYMax(){
return yMax;
}

private double fact(double n){

n--;
while(n >= 1){
n--;
}
}

private double f(double n, int curGraph) {
switch (curGraph){
case ONE:
return 1;
case N:
return n;
case N_SQUARED:
return Math.pow(n, 2);
case N_CUBED:
return Math.pow(n, 3);
case N_FOURTH:
return Math.pow(n, 4);
case LOG_N:
return Math.log(n);
case N_LOG_N:
return n*Math.log(n);
case TWO_POW_N:
return Math.pow(2, n);
case THREE_POW_N:
return Math.pow(3, n);
case N_FACTORIAL:
return fact(n);
case SQRT_N:
return Math.pow(n, .5);
case N_POINT_ONE:
return Math.pow(n, .1);
}
//return (Math.cos(x/5) + Math.sin(x/7) + 2) * getSize().height / 4;
//return (Math.pow(x, 2));
return (1);
}

private void paintGrid(Graphics2D g2d){
int height = getSize().height;
int width = getSize().width;

g2d.setPaint(Color.darkGray);
for(int i=0;i<width;i+=(float)width/10){
for(int j=0;j<height;j+=(float)height/10){
g2d.drawLine(i, height-j, i, height-j);
}
}
}

private String makeXLabel(int i){
float multiple = (((float)xMax/10)*i);
String newstring = (""+multiple);
int exponent = 0;

if(xMax < 10000){
if(xMax <= 10){
if(newstring.length() < 4)
return newstring;
else
return newstring.substring(0, 4);
}else{
return newstring.substring(0, newstring.indexOf("."));
}
}else{
while(multiple >= 10){
multiple /= 10;
exponent++;
}
return multiple+"e"+exponent;
}
}

private String makeYLabel(int i){
float multiple = (((float)yMax/10)*i);
String newstring = (""+multiple);
int exponent = 0;

if(yMax < 10000){
if(yMax <= 10){
if(newstring.length() < 4)
return newstring;
else
return newstring.substring(0, 4);
}else{
return newstring.substring(0, newstring.indexOf("."));
}
}else{
while(multiple >= 10){
multiple /= 10;
exponent++;
}
return multiple+"e"+exponent;
}
}

private void paintScale(Graphics2D g2d){
int height = getSize().height;
int width = getSize().width;
float yInc = (float)height/(float)10;
float xInc = (float)width/(float)10;
int i;
String toPaint;
g2d.setPaint(Color.black);

// Y axis
for(i=1;i<11;i++){
g2d.drawLine(2, (int)(height-((float)i*yInc)), 5, (int)(height-((float)i*yInc)));
toPaint = makeYLabel(i);
if(i < 10)
g2d.drawString(toPaint, 7, height-(i*yInc-5));
}

// X axis
for(i=1;i<11;i++){
g2d.drawLine((int)(width-(i*xInc)), height-2, (int)(width-(i*xInc)), height-5);
toPaint = makeXLabel(i);
if(i < 10)
g2d.drawString(toPaint, (i*xInc-(toPaint.length()*3)), height-7);
}

}

/*
Does the actual painting of the graphs
*/
public void paint(Graphics g){
Graphics2D g2d = (Graphics2D)g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int height = getSize().height;
int width = getSize().width;
int y1, y2;
double n;

super.paint(g);

paintGrid(g2d);

for (int x = 1 ; x < width ; x++) {
n = x;

y1 = (int)((double)const1*(f((n/width)*xMax, curGraph1)*((double)height/(double)yMax)));
y2 = (int)((double)const1*(f(((n+1)/width)*xMax, curGraph1)*((double)height/(double)yMax)));
if(y2 > height){
if(y1 > height)
break;
y2 = height;
}
if((y1 < height)){
g2d.setPaint(Color.red);
g2d.drawLine((int)n, height-y1, (int)(n + 1), height-y2);
}

}

for (int x = 1 ; x < width ; x++) {
n = x;

y1 = (int)((double)const2*(f((n/width)*xMax, curGraph2)*((double)height/(double)yMax)));
y2 = (int)((double)const2*(f(((n+1)/width)*xMax, curGraph2)*((double)height/(double)yMax)));
if(y2 > height){
if(y1 > height)
break;
y2 = height;
}
if((y1 < height)){
g2d.setPaint(new Color(0, 200, 0));
g2d.drawLine((int)n, height-y1, (int)(n + 1), height-y2);
}
}

for (int x = 1 ; x < width ; x++) {
n = x;
y1 = (int)((double)const3*(f((n/width)*xMax, curGraph3)*((double)height/(double)yMax)));
y2 = (int)((double)const3*(f(((n+1)/width)*xMax, curGraph3)*((double)height/(double)yMax)));
if(y2 > height){
if(y1 > height)
break;
y2 = height;
}
if((y1 < height)){
g2d.setPaint(Color.blue);
g2d.drawLine((int)n, height-y1, (int)(n + 1), height-y2);
}
}

paintScale(g2d);

}
private void jbInit() throws Exception {
this.setBackground(Color.white);
}
}

```