/*
  StatCalc --- a java applet for doing simple statistical calculations
 
  Copyright (C) 1998,   Stephan Pelikan

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.
  
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  

  Contact Information:

  Stephan Pelikan 
  8 Tanglewood Lane
  Cincinnati, Ohio 45224-2823
  (513) 681-2574

  or at work:

  (pelikan@math.uc.edu)
  Steve Pelikan
  Mathematical Sciences
  University of Cincinnati
  Cincinnati, OH 45221-0025
  (513) 556-4084

*/


import java.applet.Applet;
import java.util.*;
import java.awt.*;
import java.lang.Float;
import java.lang.Math;

public class StatCalc extends Applet 
{
  String Buffer;
  TextArea ta;
  Button button,button1,button2,button3,button4,button5,button6,button7,button8;
  Panel panel,bottom_panel;
  float data[];
  GridBagLayout gridbag= new GridBagLayout();
  private String Round(float x,int decimals)    
  {
    double xx=x;
    double factor=Math.pow(10.0,(double)decimals);
    double temp=Math.floor(factor*xx+0.5)/factor;
    String ans=""+temp;
    return ans;
  }
private String Round(double x,int decimals)    
  {
    double xx=x;
    double factor=Math.pow(10.0,(double)decimals);
    double temp=Math.floor(factor*xx+0.5)/factor;
    String ans=""+temp;
    return ans;
  }
    
  private void bubble(float d[],int n)
  {
    int j,pass,switched=1;
    float temp;
    for(pass=0;pass<n-1 &&switched==1;pass++)
      {
	switched=0;
	for(j=0;j<n-1-pass;j++)
	  {
	    if(d[j]>d[j+1])
	      {
		switched=1;
		temp=d[j];
		d[j]=d[j+1];
		d[j+1]=temp;
	      }
	  }
      }
  }
 
  
  public void init() {
    
    ta = new TextArea("",8,60);
    ta.setFont(new Font("Courier",Font.PLAIN,12));
    
    button = new Button("Compute");
    button1 = new Button("Sort");
    button2= new Button("Clear");
    button3 = new Button("Histogram");
    button4=new Button("Regression");
    button5=new Button("ChiSquare");
    button6=new Button("Copy");
    button7=new Button("Paste");
    button8=new Button("tTest");
    panel=new Panel();
    bottom_panel=new Panel();
    panel.setLayout(gridbag);
    bottom_panel.setLayout(gridbag);
    /*
    constrain(panel,button,0,0,1,1);
    constrain(panel,button1,1,0,1,1);
    constrain(panel,button2,2,0,1,1);
    constrain(panel,button3,3,0,1,1);
    constrain(panel,button4,4,0,1,1);
    constrain(panel,button5,5,0,1,1);
    constrain(panel,button6,6,0,1,1);
    constrain(panel,button7,7,0,1,1);
    constrain(panel,button8,8,0,1,1);
*/
    //constrain(panel,button2,0,0,1,1);
    //constrain(panel,button6,1,0,1,1);
    constrain(panel,button,0,0,1,1);
    constrain(panel,button3,1,0,1,1);
    constrain(panel,button4,4,0,1,1);
    //constrain(panel,button7,0,1,1,1);
    constrain(panel,button5,3,0,1,1);
    constrain(panel,button1,2,0,1,1);
    constrain(panel,button8,5,0,1,1);
    constrain(bottom_panel,button2,0,0,1,1);
constrain(bottom_panel,button6,1,0,1,1);
constrain(bottom_panel,button7,2,0,1,1);
    this.setLayout(gridbag);
    constrain(this,panel,0,0,1,1);
    constrain(this,ta,0,1,1,1);
constrain(this,bottom_panel,0,2,1,1);
  }
  
  
  public boolean action(Event e, Object arg)
  {
    if(arg.equals("Copy")) Buffer=ta.getText();
    if(arg.equals("Paste")) ta.setText(Buffer);
    if(arg.equals("ChiSquare"))
    {
      int i,j;
      String mydata= ta.getText();
      StringTokenizer ST=new StringTokenizer(mydata,"\n");
      int ROWS= ST.countTokens();
      ta.setText("ROWS="+ROWS);
      //If ROWS <=1 explain
      String CurrentLine= ST.nextToken();
      StringTokenizer STT=new StringTokenizer(CurrentLine," \t,");
      int COLS= STT.countTokens();
      float data[][]=new float[ROWS+1][COLS+1];
      for(i=0;i<COLS;i++) data[0][i] =Float.valueOf(STT.nextToken()).floatValue();
      for(j=1;j<ROWS;j++)
      {
	  CurrentLine= ST.nextToken();
	  StringTokenizer STTT=new StringTokenizer(CurrentLine," \t,");
	  for(i=0;i<COLS;i++) data[j][i] =Float.valueOf(STTT.nextToken()).floatValue();
      }
      float expect[][]=new float[ROWS+1][COLS+1];
      for(j=0;j<ROWS;j++)
	{
	  data[j][COLS]=(float)0.0;
	  for(i=0;i<COLS;i++) data[j][COLS] += data[j][i];
	  expect[j][COLS]=data[j][COLS];
	}
      for(i=0;i<COLS;i++)
	{
	  data[ROWS][i]=(float)0.0;
	  for(j=0;j<ROWS;j++) data[ROWS][i]+= data[j][i];
	  expect[ROWS][i]=data[ROWS][i];
	}
      float Total=(float) 0.0;
      for(j=0;j<ROWS;j++) Total +=data[j][COLS];
      expect[ROWS][COLS]=data[ROWS][COLS]=Total;
      for(i=0;i<ROWS;i++)
	{
	  for(j=0;j<COLS;j++) expect[i][j]=expect[i][COLS]*expect[ROWS][j]/Total;
	}
      String temp;
      int maxwidth=0;
      String tmp="";
      temp="Observed\n";
      for(i=0;i<=ROWS;i++)
	{
	  for(j=0;j<=COLS;j++)
	    {
	      tmp=Round(data[i][j],2);
	      if(maxwidth < tmp.length()) maxwidth=tmp.length();
	    }
	}
      maxwidth++;
      for(i=0;i<=ROWS;i++)
	{
	  for(j=0;j<=COLS;j++)
	    {
	      tmp=Round(data[i][j],2);
	      while(tmp.length()<=maxwidth) tmp = tmp+ " ";
	      temp = temp +  tmp;
	    }
	  temp += "\n";
	}
      temp+= "\nExpected\n";
      //find max width of entries in table
      maxwidth=0;
      for(i=0;i<=ROWS;i++)
	{
	  for(j=0;j<=COLS;j++)
	    {
	      tmp=Round(expect[i][j],2);
	      if(maxwidth < tmp.length()) maxwidth=tmp.length();
	    }
	}
      maxwidth++;
      //temp = temp + "maxwidth =" + maxwidth+"\n";
      for(i=0;i<=ROWS;i++)
	{
	  for(j=0;j<=COLS;j++)
	    {
	      tmp=Round(expect[i][j],2);
	      while(tmp.length()<=maxwidth) tmp = tmp+ " ";
	      temp = temp +  tmp;
	    }
	  temp = temp+"\n";
	}
      float Chi=(float)0.0;
      for(i=0;i<ROWS;i++)
	{
	  for(j=0;j<COLS;j++) Chi += (data[i][j]-expect[i][j])*(data[i][j]-expect[i][j])/expect[i][j];
	}
      temp += "\nChi-square = "+Round(Chi,4)+"\n";
      int df= (ROWS-1)*(COLS-1);
      temp += "df = "+df;
      ta.setText(temp);
    }

    if(arg.equals("tTest"))
      {
	int i;
	String Result;
	Result="";
	String tempstring;
	String mydata=ta.getText();
	StringTokenizer ST = new StringTokenizer(mydata,"\n");
	int n=ST.countTokens();
	float x[],y[];
	int xsize,ysize;
	x= new float[n];
	y=new float[n];
	xsize=0;
	ysize=0;
	int group=0;
	 StringTokenizer STT;
	for(i=0;i<n;i++)
	  {
	    Result += "Line number " + i +"\n";
	    tempstring = ST.nextToken();
	    Result += tempstring+"\n";
	    STT = new StringTokenizer(tempstring," \t,");
	    if (STT.countTokens()==0 && group==0)
	      {
		group = 1;
		Result += "switching to next group\n";
	      }
	    while(STT.hasMoreTokens()&& xsize <n && ysize < n)
	    {
	      tempstring=STT.nextToken();
	      Result += "|"+ tempstring+"|";
	      if(group==0) x[xsize++] =Float.valueOf(tempstring).floatValue();
	      else y[ysize++] =Float.valueOf(tempstring).floatValue();
	    }
	  }
	/*
	for(i=0;i<n;i++)
	  {
	    float temp1,temp2;
	    StringTokenizer STT = new StringTokenizer(ST.nextToken()," \t,");
	    temp1= Float.valueOf(STT.nextToken()).floatValue();
	    temp2= Float.valueOf(STT.nextToken()).floatValue();
	    if(temp1==1) x[xsize++]=temp2;
	    else if(temp1==2) y[ysize++]=temp2;
	  }
	  */
	double mx,my,mmx,mmy;
	double sx,sy;
	mx=0;
	my=0;
	mmx=0;
	mmy=0;
	for(i=0;i<xsize;i++)
	  {
	    mx += x[i];
	    mmx += x[i]*x[i];
	  }
	sx=(xsize*mmx-mx*mx)/(xsize*(xsize-1));
	sx=Math.sqrt(sx );
	mx=mx/xsize;
	for(i=0;i<ysize;i++)
	  {
	    my += y[i];
	    mmy += y[i]*y[i];
	  }
	sy=Math.sqrt( (ysize*mmy-my*my)/(ysize*(ysize-1)));
	my=my/ysize;
	
	Result += "Group 1: n1 =" + xsize + " avg =" +mx + " std dev =" + sx+"\n";
	Result += "Group 2: n2 =" + ysize + " avg =" +my + " std dev =" + sy+"\n";
	double t;
	t=(mx-my)/Math.sqrt((1.0/xsize+1.0/ysize)*(xsize*sx*sx+ysize*sy*sy)/(xsize+ysize-2));
	double df= xsize+ysize-2;
	Result += "Same variances: T= " +Round(t,4)+" df = "+df+"\n";
	t=(mx-my)/Math.sqrt((1.0/xsize+1.0/ysize)*(sx*sx+sy*sy));
	if( xsize < ysize) df=xsize;
	else df= ysize;
	Result += "Conservative different variances: T= " +Round(t,4)+" df = "+df+"\n";
	ta.setText(Result);
	
      }
    if(arg.equals("Regression"))
      {
	int i;
	String tempstring;
	String mydata=ta.getText();
	StringTokenizer ST = new StringTokenizer(mydata,"\n");
	int n=ST.countTokens();
	float x[],y[];
	x= new float[n];
	y=new float[n];
	for(i=0;i<n;i++)
	  {
	    StringTokenizer STT = new StringTokenizer(ST.nextToken()," \t,");
	    x[i]= Float.valueOf(STT.nextToken()).floatValue();
	    y[i]= Float.valueOf(STT.nextToken()).floatValue();
	  }
	float Sxy,Sxx,Sx,Sy,Syy,b1,b0,r;
	Sxy=(float)0.0;
	Sxx=(float)0.0;
	Syy=(float)0.0;
	Sx=(float)0.0;
	Sy=(float)0.0;
	for(i=0;i<n;i++)
	  {
	    Sxy += x[i]*y[i];
	    Syy += y[i]*y[i];
	    Sx += x[i];
	    Sy += y[i];
	    Sxx += x[i]*x[i];
	  }
	b1= (n*Sxy-Sx*Sy)/(n*Sxx-Sx*Sx);
	b0=(Sy-b1*Sx)/n;
	r=(float)((n*Sxy-Sx*Sy)/Math.sqrt((n*Sxx-Sx*Sx)*(n*Syy-Sy*Sy)));
	tempstring="The least squares line is: y="+(b0)+ " + "+(b1)+"*x\n";
	tempstring+="The correlation coefficient is r= "+(r)+"\n";
	ta.setText(tempstring);
	
      }
    if(arg.equals("Sort")){
      String mydata= ta.getText();
      String temp;
      int n,i;
      float m,mm,mt,s,med;
      
      double d,f;
      //System.out.println(mydata);
      StringTokenizer ST = new StringTokenizer(mydata," 	,\n");
      n=ST.countTokens();
      data=new float[n];
      //i=0;
      if(n > 0)
	{
	  i=0;
	  m=0;
	  mm=0;
	  while(ST.hasMoreTokens())
	    {
	      temp=ST.nextToken();
	      mt =Float.valueOf(temp).floatValue();
	      data[i++]=mt;
	      m+= mt;
	      mm += mt*mt;
	    }
	  bubble(data,n);
	  temp="";
	  for(i=0;i<n;i++){ temp = temp+data[i]+" ";}
	  ta.setText(temp+"\n");
	}
      return true;
    }
    
    if(arg.equals("Histogram")){
      String mydata= ta.getText();
      String temp,mylabel;
      int n,i,BINS,j;
      float m,mm,mt,s,med,step;
      
      double d,f;
      //System.out.println(mydata);
      StringTokenizer ST = new StringTokenizer(mydata," 	,\n");
      n=ST.countTokens();
      data=new float[n];
      //i=0;
      if(n > 0)
	{
	  i=0;
	  m=0;
	  mm=0;
	  while(ST.hasMoreTokens())
	    {
	      temp=ST.nextToken();
	      mt =Float.valueOf(temp).floatValue();
	      data[i++]=mt;
	      m+= mt;
	      mm += mt*mt;
	    }
	  bubble(data,n);
	  //now make histogram
	  // range = data[n-1]-data[0]
	  if(n < 60) BINS=5;
	  else BINS = 7;
	  step = (data[n-1]-data[0])/BINS;
	  
	  temp="\n";
	  j=0;
	  for(i=1;i<=BINS;i++)
	    {
	      while( j < n && data[j] <= data[0]+i*step)
				{
				  temp = temp + "x";
				  j++;
				}
	      mylabel="";
	      if(i==1)
		mylabel = mylabel +"["+ (data[0]+(i-1)*step) + "-" +(data[0]+i*step)+"]";
	      else mylabel = mylabel +"("+ (data[0]+(i-1)*step) + "-" +(data[0]+i*step)+"]";
			
	      temp = temp + "               "+ mylabel + "\n";
	    }
	  
	  //for(i=0;i<n;i++){ temp = temp+data[i]+" ";}
	  ta.setText(temp+"\n");
	}
      return true;
    }
    else if(arg.equals("Compute")){
      
      String mydata= ta.getText();
      String temp,tmp;
      int n,i;
      float m,mm,mt,s,med,q1,q3;
      
      double d,f;
      //System.out.println(mydata);
      StringTokenizer ST = new StringTokenizer(mydata," 	,\n");
      n=ST.countTokens();
      data=new float[n];
      //i=0;
      if(n > 0)
	{
	  i=0;
	  m=0;
	  mm=0;
	  while(ST.hasMoreTokens())
	    {
	      temp=ST.nextToken();
	      mt =Float.valueOf(temp).floatValue();
	      data[i++]=mt;
	      m+= mt;
	      mm += mt*mt;
	    }
	  
	  d = (n*mm - m*m)/(n*(n-1));
	  d=Math.sqrt(d);	
	  m = m/n;
	  bubble(data,n);
	  f=n;
	  //Find median; median rank is (n+1)/2 
	  //And the corresponding value is located at (n+1)/2 -1 =(n-1)/2
	  //or is the average of (n-1)/2 \pm (1/2) = n/2-1 and n/2
	  if(f/2 == Math.floor(f/2)) {med=(data[n/2-1]+data[n/2])/2;}
	  else {med= data[(n-1)/2];}
	  //The quartile rank is (Integer(median rank) +1)/2
	  double quartilerank= (Math.floor((f+1)/2)+1)/2;
	  //if quartilerank is an integer, subtract 1 to get the data values' index
	  if(Math.floor(quartilerank)==quartilerank)
	  {
	      q1= data[(int)quartilerank-1];
	      q3= data[n-(int)quartilerank];
	  }
	  else
	  {
	    q1=(data[(int)(quartilerank-1.5)]+ data[(int)(quartilerank-0.5)])/2;
	    q3=(data[n-(int)(quartilerank-0.5)]+ data[n-(int)(quartilerank+0.5)])/2;
	  }
	 tmp=Round(d,4);
	  ta.setText(mydata+"\nN is: "+n+"\nMean is: "+m+"\nStd Dev is: " + tmp +"\n\nQ1 is: "+q1+"\nMedian is: "+med+"\nQ3 is: "+ q3+"\n");
	}
      return true;}
    else if(arg.equals("Clear")){
      ta.setText(""); return true;
    }
    
    return false;
  }
  

  public void start() {
  }
  
 
  public void stop() {
  }
  
  
  public void destroy() {
  }
  public void constrain(Container container, Component component, 
			int grid_x, int grid_y, int grid_width, int grid_height,
			int fill, int anchor, double weight_x, double weight_y,
                  int top, int left, int bottom, int right)
  {
    GridBagConstraints c = new GridBagConstraints();
    c.gridx = grid_x; c.gridy = grid_y;
    c.gridwidth = grid_width; c.gridheight = grid_height;
    c.fill = fill; c.anchor = anchor;
    c.weightx = weight_x; c.weighty = weight_y;
    if (top+bottom+left+right > 0)
      c.insets = new Insets(top, left, bottom, right);
    
    ((GridBagLayout)container.getLayout()).setConstraints(component, c);
    container.add(component);
  }
  public void constrain(Container container, Component component, 
			int grid_x, int grid_y, int grid_width, int grid_height) {
    constrain(container, component, grid_x, grid_y, 
              grid_width, grid_height, GridBagConstraints.NONE, 
              GridBagConstraints.NORTHWEST, 0.0, 0.0, 0, 0, 0, 0);
    }
  
  public void constrain(Container container, Component component, 
			int grid_x, int grid_y, int grid_width, int grid_height,
			int top, int left, int bottom, int right) {
    constrain(container, component, grid_x, grid_y, 
              grid_width, grid_height, GridBagConstraints.NONE, 
              GridBagConstraints.NORTHWEST, 
              0.0, 0.0, top, left, bottom, right);
    }
  
  
  
}