import java.awt.*;
import java.applet.*;
import java.util.*;
import java.awt.event.*;
import java.lang.String;
import java.lang.*;




public class PlotPoints extends Applet {  
	Graphics offScreenG;
	Image offScreenImg, backImg;
	Font small = new Font("Times New Roman", Font.BOLD, 20);
	Font medium = new Font("Times New Roman", Font.BOLD, 35);
	Font big = new Font("Times New Roman", Font.BOLD, 50);
	int X, Y;
	float multiplier;
	float limit;
	boolean plot, showLine, slopeDefined, inError;
	int numPointsOutOfRange;
	float yIntercept, slope; // Regression Line: y = yIntercept + slope*x
	float xIntercept;

	float drawLineXPoint1, drawLineYPoint1, drawLineXPoint2, drawLineYPoint2;

	Button OneByOne, TenByTen, FiftyByFifty, HundByHund;
	Button PlotPoints;
	Button Reset;
	Button Regression;

	TextField[] xs = new TextField[10];
	TextField[] ys = new TextField[10];

	String[] pointNames = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J"};
	boolean[] pointNotInRange = new boolean[10];

	String whichGrid = "back10by10.gif";
	
	public void init() {

		backImg = getImage(getCodeBase(), whichGrid);
		offScreenImg = createImage(this.getSize().width, this.getSize().height);
		offScreenG = offScreenImg.getGraphics();
		repaint();
	
		setLayout(null);

		OneByOne = new Button(); OneByOne.setLabel("1 by 1"); OneByOne.setBounds(8, 325, 66, 25); add(OneByOne);
		TenByTen = new Button(); TenByTen.setLabel("10 by 10"); TenByTen.setBounds(77, 325, 66, 25); add(TenByTen);
		FiftyByFifty = new Button(); FiftyByFifty.setLabel("50 by 50"); FiftyByFifty.setBounds(146, 325, 66, 25); add(FiftyByFifty);
		HundByHund = new Button(); HundByHund.setLabel("100 by 100"); HundByHund.setBounds(215, 325, 66, 25); add(HundByHund);
		PlotPoints = new Button(); PlotPoints.setLabel("Plot My Points"); PlotPoints.setBounds(285, 2, 120, 20); add(PlotPoints);
		Regression = new Button(); Regression.setLabel("Show Line of Best Fit"); Regression.setBounds(410, 2, 130, 20); add(Regression);
		Reset = new Button(); Reset.setLabel("Reset"); Reset.setBounds(545, 2, 50, 20); add(Reset);


		for (int i = 0; i < 10; i++)
		{
			xs[i] = new TextField(3);
			xs[i].setBounds(123, 77 + 22*i, 33, 19);
			add(xs[i]);
			ys[i] = new TextField(0);
			ys[i].setBounds(167, 77 + 22*i, 36, 19);
			add(ys[i]);
			pointNotInRange[i] = false;
		}

		multiplier = 30;
		limit = 10;
		
	}

	public void paint (Graphics g){

		backImg = getImage(getCodeBase(), whichGrid);
		offScreenG.drawImage(backImg,0,0,this);
		g.setFont(small);
		g.setColor(new Color(67, 113, 54)); 
		g.drawImage(offScreenImg,0,0,this);

		numPointsOutOfRange = 0;

		inError = false;
		for (int i = 0; i < 10; i++)
			pointNotInRange[i] = false;

		if (plot)
		{
			for (int i = 0; i < 10; i++)
			{

				if ( (!xs[i].getText().equals("") && ys[i].getText().equals("") ) || (xs[i].getText().equals("") && !ys[i].getText().equals("") ) )
				{
					pointNotInRange[i] = true;
					numPointsOutOfRange++;
					inError = true;
				}

				if (!xs[i].getText().equals("") && !ys[i].getText().equals(""))
				{
					float xVal, yVal;

					xVal = Float.parseFloat(xs[i].getText());
					yVal = Float.parseFloat(ys[i].getText());

					if (xVal >= 0 && xVal <= limit && yVal >= 0 && yVal <= limit)
					{
						int xPixels = 287 + (int)(xVal*multiplier);
						int yPixels = 327 - (int)(yVal*multiplier);
						g.fillRect(xPixels, yPixels, 7, 7);
						pointNotInRange[i] = false;
					}
					else
					{
						pointNotInRange[i] = true;					
						numPointsOutOfRange++;
						inError = true;
					}
				}
			}

			if (numPointsOutOfRange > 0)
			{
				g.setColor(new Color(255, 156, 0));
				g.fillRect(291, 120, 299, 10);
				g.fillRect(291, 230, 299, 10);
				g.setColor(new Color(255, 255, 255));
				g.fillRect(291, 130, 299, 100);
				g.setColor(new Color(33, 39, 162));

				int printErrorXVal = 300;

				if (numPointsOutOfRange == 1)
				{
					for (int i = 0; i < 10; i++)
						if (pointNotInRange[i])
						{
							g.drawString(pointNames[i] + " is out of range.", 300, 175);
							g.drawString("Adjust this value in your chart.", 300, 195);
						}
				}
				else
				{
					for (int i = 0; i < 10; i++)
						if (pointNotInRange[i])
						{
							if (numPointsOutOfRange != 1)
							{
								if (numPointsOutOfRange != 2)
									g.drawString(pointNames[i] + ", ", printErrorXVal, 165);
								else
									g.drawString(pointNames[i] + " and ", printErrorXVal, 165);
								printErrorXVal += 25;
								numPointsOutOfRange--;
							}
							else
							{
								g.drawString(pointNames[i], printErrorXVal + 35, 165);
								g.drawString("are out of range.", 300, 185);
								g.drawString("Adjust these values in your chart.", 300, 205);
								i = 10;
							}
						}
				}
			}			

		}

		if (showLine)
		{
			DetermineRegressionLine();

			g.drawLine(290 + (int)(drawLineXPoint1*multiplier) + 1, 330 - (int)(drawLineYPoint1*multiplier), 290 + (int)(drawLineXPoint2*multiplier) + 1, 330 - (int)(drawLineYPoint2*multiplier));	
			g.drawLine(290 + (int)(drawLineXPoint1*multiplier), 330 - (int)(drawLineYPoint1*multiplier), 290 + (int)(drawLineXPoint2*multiplier), 330 - (int)(drawLineYPoint2*multiplier));		
			g.drawLine(290 + (int)(drawLineXPoint1*multiplier), 330 - (int)(drawLineYPoint1*multiplier) + 1, 290 + (int)(drawLineXPoint2*multiplier), 330 - (int)(drawLineYPoint2*multiplier) + 1);	

		}
		
	}
			


	public void update (Graphics g) {
		paint(g);
	}

	public void DetermineRegressionLine(){
	
		slopeDefined = false;		

		int pointCount = 0;
		float[] xVals = new float[10];
		float[] yVals = new float[10];
		float sumXs = 0, sumYs = 0;
		float meanXs = 0, meanYs = 0;
		float sumDiffXsTimesdiffYs = 0;
		float sumDiffXsSquared = 0;
		float xValWhenYIsLimit, yValWhenXIsLimit;

		for (int i = 0; i < 10; i++)
			if (!xs[i].getText().equals("") && !ys[i].getText().equals(""))
			{
				xVals[i] = Float.parseFloat(xs[i].getText());
				yVals[i] = Float.parseFloat(ys[i].getText());

				if (xVals[i] >= 0 && xVals[i] <= limit && yVals[i] >= 0 && yVals[i] <= limit)
				{
					pointCount++;
					sumXs += xVals[i];
					sumYs += yVals[i];
				}
			}

		meanXs = sumXs/pointCount;
		meanYs = sumYs/pointCount;

		for (int i = 0; i < pointCount; i++)
		{
			if (xVals[i] >= 0 && xVals[i] <= limit && yVals[i] >= 0 && yVals[i] <= limit)
			{
				sumXs += xVals[i];
				sumYs += yVals[i];
			}

			sumDiffXsTimesdiffYs += (xVals[i] - meanXs)*(yVals[i] - meanYs);
			sumDiffXsSquared += (xVals[i] - meanXs)*(xVals[i] - meanXs);
		}		

		if (sumDiffXsSquared != 0)
		{
			slopeDefined = true;
			slope = sumDiffXsTimesdiffYs/sumDiffXsSquared;
		}

		yIntercept = meanYs - slope*meanXs;	

		xIntercept = -1*yIntercept/slope;	
		yValWhenXIsLimit = slope*limit + yIntercept;
		xValWhenYIsLimit = (yIntercept - limit)/(-1*slope);

		if (slopeDefined)
		{
			if (slope > 0)
			{
				if (xIntercept >= 0 && xIntercept <= limit)
				{
					drawLineXPoint1 = xIntercept;
					drawLineYPoint1 = 0;
			
					if (xValWhenYIsLimit >= 0 && xValWhenYIsLimit <= limit)
					{
						drawLineXPoint2 = xValWhenYIsLimit;
						drawLineYPoint2 = limit;
					}
					else
					{
						drawLineXPoint2 = limit;
						drawLineYPoint2 = yValWhenXIsLimit;
					}
				}
				else 
				{
					drawLineXPoint1 = 0;
					drawLineYPoint1 = yIntercept;

					if (xValWhenYIsLimit >= 0 && xValWhenYIsLimit <= limit)
					{
						drawLineXPoint2 = xValWhenYIsLimit;
						drawLineYPoint2 = limit;
					}
					else
					{
						drawLineXPoint2 = limit;
						drawLineYPoint2 = yValWhenXIsLimit;
					}
				}
			}
			else if (slope < 0)
			{
				if (yIntercept >= 0 && yIntercept <= limit)
				{
					drawLineXPoint1 = 0;
					drawLineYPoint1 = yIntercept;

					if (xIntercept >= 0 && xIntercept <= limit)
					{
						drawLineXPoint2 = xIntercept;
						drawLineYPoint2 = 0;
					}
					else 
					{
						drawLineXPoint2 = limit;
						drawLineYPoint2 = yValWhenXIsLimit;
					}
				}
				else
				{
					drawLineXPoint1 = xValWhenYIsLimit;
					drawLineYPoint1 = limit;

					if (xIntercept >= 0 && xIntercept <= limit)
					{
						drawLineXPoint2 = xIntercept;
						drawLineYPoint2 = 0;
					}
					else 
					{
						drawLineXPoint2 = limit;
						drawLineYPoint2 = yValWhenXIsLimit;
					}
				}
			}
			else // slope = 0
			{
				drawLineXPoint1 = 0;
				drawLineXPoint2 = limit;
				drawLineYPoint1 = drawLineYPoint2 = yIntercept;
			}
		}
		else
		{
			drawLineXPoint1 = drawLineXPoint2 = meanXs;
			drawLineYPoint1 = 0;
			drawLineYPoint2 = limit;
		}
				 

		System.out.println("YIntercept: " + yIntercept);
		System.out.println("XIntercept: " + xIntercept);
		System.out.println("X Value When Y is " + limit + ": " + xValWhenYIsLimit);
		System.out.println("Y Value When X is " + limit + ": " + yValWhenXIsLimit);
		System.out.println("Slope: " + slope);


	}	

	public void Reset(){

		for (int i = 0; i < 10; i++)
		{
			xs[i].setText("");
			ys[i].setText("");
		}
			
		Regression.setLabel("Show Line of Best Fit");

		multiplier = 30;
		limit = 10;
		plot = showLine = slopeDefined = inError = false;
		numPointsOutOfRange = 0;
		yIntercept = slope = xIntercept;

		repaint();

	}


	public boolean action(Event evt, Object arg) {

		if (arg.equals("1 by 1"))
		{
			whichGrid = "back1by1.gif";
			multiplier = 300;
			limit = 1;
		}

		if (arg.equals("10 by 10"))
		{
			whichGrid = "back10by10.gif";
			multiplier = 30;
			limit = 10;
		}

		if (arg.equals("50 by 50"))
		{
			whichGrid = "back50by50.gif";
			multiplier = 6;
			limit = 50;
		}

		if (arg.equals("100 by 100"))
		{
			whichGrid = "back100by100.gif";
			multiplier = 3;
			limit = 100;
		}

		if (arg.equals("Reset"))
			Reset();

		if (arg.equals("Plot My Points"))
			plot = true;

		if (arg.equals("Show Line of Best Fit"))
		{
			if (!inError)
			{
				showLine = true;
				Regression.setLabel("Hide Line of Best Fit");
			}
		}

		if (arg.equals("Hide Line of Best Fit"))
		{
			showLine = false;
			Regression.setLabel("Show Line of Best Fit");
		}

		repaint();

		return true;
	}			

}