Resizing a window containing a graph

Question

I have created a class that plots points on a graph using two arrays passed to the class. One array is for the x-values, the other is for the y-values. Initially, the graph is fine. When I minimize or maximize the window, the values in the arrays change and causes the points to disappear. If I restore the window to the original size, the points are still gone. Why are the values in my array changing? Here is the code:
//Graph_Lin.java
//Graphs thermodynamic properties
import java.util.Scanner;
import java.awt.Graphics;
import javax.swing.JPanel;
public class Graph_Lin extends JPanel
  private int x1, y1, x2, y2;
  public double x[], y[];
  public double xpoint[], ypoint[];
  private double xmax = 0;
  private double ymax = 0;
  private double xmin, ymin, xrange, yrange;
  //constructor sets coordinates of axes
  public Graph_Lin( double xdata[], double ydata[] )
    x = xdata;
    y = ydata;
    xpoint = xdata;
    ypoint = ydata;
      xmin = x[0];
      ymin = y[0];
      int j = 0;
      while ( x[j] > 0)
        if ( x[j] > xmax)
       xmax = x[j];
     if ( y[j] > ymax)
         ymax = y[j];
        if ( x[j] < xmin)
       xmin = x[j];
     if ( y[j] < ymin)
         ymin = y[j];
     j++;
      yrange = ymax - ymin;
      xrange = xmax - xmin;
    public void paintComponent( Graphics g )
      super.paintComponent( g );
      x1 = getx1();
      x2 = getx2();
      y1 = gety1();
      y2 = gety2();
      g.drawLine(x1, y1, x2, y1);
      g.drawLine(x1, y1, x1, y2);
//*****create the points for plotting*************
      int diam = 10;  //diameter of data point in pixels, should be an even number
      for ( int i = 0; i < x.length; i++ )
     xpoint[i] = (x[i]-xmin)/xrange*(x2-x1)+x1 - diam/2;
     ypoint[i] = y1 - (y[i]-ymin)/yrange*(y1-y2) - diam/2;
      for ( int i = 0; i < x.length; i++ )
       g.drawOval( ((int) xpoint),((int) ypoint[i]),diam,diam);
//*****get values for the x and y axes****************
public int getx1()
return x1 = (int) (.05 * getWidth());
public int gety1()
return y1 = (int) (.95 * getHeight());
public int getx2()
return x2 = (int) (.95 * getWidth());
public int gety2()
return y2 = (int) (.05 * getHeight());
//*****end get values for the x and y axes************

Answer 1

What is an SSCCE? Here are the other files. I think I got them all.
//LiquidDensity.java
//This class calculates and returns density for water vapor
//First, it calculates specific volume.  Then it returns the reciprocal as density
public class LiquidDensity
  public double getv(double T)
      double kv = 1;          //kv represents specific volume x 10^3
      double Th, Tl, kh, kl;     //kh is spec vol at Th, kl is spec vol at Tl
     if (T >= 645 && T <= 647.3)
          Th = 647.3;
          Tl = 645;
            kh = 3.170;
          kl = 2.351;
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 640 && T <= 645)
          Tl = 640;
          Th = Tl+5;
            kl = 2.075;
          kh = 2.351;
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 635 && T <= 640)
          Tl = 635;
          Th = Tl+5;
            kl = 1.935;
          kh = 2.075;
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 630 && T <= 635)
          Tl = 630;     //mod
          Th = Tl+5;
            kl = 1.856;     //mod
          kh = 1.935;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 625 && T <= 630)
          Tl = 625;     //mod
          Th = Tl+5;
            kl = 1.778;     //mod
          kh = 1.856;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 620 && T <= 625)
          Tl = 620;     //mod
          Th = Tl+5;
            kl = 1.705;     //mod
          kh = 1.778;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 610 && T <= 620)
          Tl = 610;     //mod
          Th = Tl+10;
            kl = 1.612;     //mod
          kh = 1.705;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 600 && T <= 610)
          Tl = 600;     //mod
          Th = Tl+10;
            kl = 1.541;     //mod
          kh = 1.612;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 590 && T <= 600)
          Tl = 590;     //mod
          Th = Tl+10;
            kl = 1.482;     //mod
          kh = 1.541;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 580 && T <= 590)
          Tl = 580;     //mod
          Th = Tl+10;
            kl = 1.433;     //mod
          kh = 1.482;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 570 && T <= 580)
          Tl = 570;     //mod
          Th = Tl+10;
            kl = 1.392;     //mod
          kh = 1.433;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 560 && T <= 570)
          Tl = 560;     //mod
          Th = Tl+10;
            kl = 1.355;     //mod
          kh = 1.392;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 550 && T <= 560)
          Tl = 550;     //mod
          Th = Tl+10;
            kl = 1.323;     //mod
          kh = 1.355;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 540 && T <= 550)
          Tl = 540;     //mod
          Th = Tl+10;
            kl = 1.294;     //mod
          kh = 1.323;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 530 && T <= 540)
          Tl = 530;     //mod
          Th = Tl+10;
            kl = 1.268;     //mod
          kh = 1.294;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 520 && T <= 530)
          Tl = 520;     //mod
          Th = Tl+10;
            kl = 1.244;     //mod
          kh = 1.268;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 510 && T <= 520)
          Tl = 510;     //mod
          Th = Tl+10;
            kl = 1.222;     //mod
          kh = 1.244;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 500 && T <= 510)
          Tl = 500;     //mod
          Th = Tl+10;
            kl = 1.203;     //mod
          kh = 1.222;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 490 && T <= 500)
          Tl = 490;     //mod
          Th = Tl+10;
            kl = 1.184;     //mod
          kh = 1.203;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 480 && T <= 490)
          Tl = 480;     //mod
          Th = Tl+10;
            kl = 1.167;     //mod
          kh = 1.184;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 470 && T <= 480)
          Tl = 470;     //mod
          Th = Tl+10;
            kl = 1.152;     //mod
          kh = 1.167;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 460 && T <= 470)
          Tl = 460;     //mod
          Th = Tl+10;
            kl = 1.137;     //mod
          kh = 1.152;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 450 && T <= 460)
          Tl = 450;     //mod
          Th = Tl+10;
            kl = 1.123;     //mod
          kh = 1.137;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 440 && T <= 450)
          Tl = 440;     //mod
          Th = Tl+10;
            kl = 1.110;     //mod
          kh = 1.123;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 430 && T <= 440)
          Tl = 430;     //mod
          Th = Tl+10;
            kl = 1.099;     //mod
          kh = 1.110;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 420 && T <= 430)
          Tl = 420;     //mod
          Th = Tl+10;
            kl = 1.088;     //mod
          kh = 1.099;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 410 && T <= 420)
          Tl = 410;     //mod
          Th = Tl+10;
            kl = 1.077;     //mod
          kh = 1.088;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 400 && T <= 410)
          Tl = 400;     //mod
          Th = Tl+10;
            kl = 1.067;     //mod
          kh = 1.077;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 390 && T <= 400)
          Tl = 390;     //mod
          Th = Tl+10;
            kl = 1.058;     //mod
          kh = 1.067;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 385 && T <= 390)
          Tl = 385;     //mod
          Th = Tl+5;
            kl = 1.053;     //mod
          kh = 1.058;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 380 && T <= 385)
          Tl = 380;     //mod
          Th = Tl+5;
            kl = 1.049;     //mod
          kh = 1.053;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 375 && T <= 380)
          Tl = 375;     //mod
          Th = Tl+5;
            kl = 1.045;     //mod
          kh = 1.049;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 373.15 && T <= 375)
          Tl = 373.15;     //mod
          Th = 375;
            kl = 1.044;     //mod
          kh = 1.045;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     else if (T >= 370 && T <= 373.15)
          Tl = 370;     //mod
          Th = 373.15;
            kl = 1.041;     //mod
          kh = 1.044;     //mod
          kv = (((kh-kl)/(Th-Tl))*(T-Th)+kh)*Math.pow(10, -3);
     return 1/kv;          //returns liquid density for specified temperature
}Next file
//A Test program
//John Abbitt
//November 29, 2006
import javax.swing.JFrame;     //import class JOptionPane
public class Test
  public static void main( String args[] )
    double array1[] = new double[200];
    double array2[] = new double[200];
    LiquidDensity dl = new LiquidDensity();
    //Conductivity c = new Conductivity();
    //SpecificVolumeG g = new SpecificVolumeG();
    double T = 370;
    for (int i = 0; i <56; i++)
      array1[i] = T;
      array2[i] = dl.getv(T)  ;
      T=T+5;
    //Test the graph
    JTabbedPaneSetUp application = new JTabbedPaneSetUp(array1, array2);
    application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
    application.setSize( 400, 400 );
    application.setVisible( true );
}Next file
//A Test program
//John Abbitt
//November 29, 2006
import javax.swing.*;     //import class JOptionPane
public class JTabbedPaneSetUp extends JFrame
  public double x[], y[];
  public JTabbedPaneSetUp(double array1[], double array2[])
    super( "Graph Program" );
    x = array1;
    y = array2;
    Graph_Lin graph1 = new Graph_Lin(x, y);
    Graph_Log graph2 = new Graph_Log(x, y);
    JTabbedPane tabbedPane = new JTabbedPane();
    //set up panel1 and add it to JTabbedPane
    JPanel panel1 = new JPanel();
    tabbedPane.addTab( "Linear", null, graph1, "Displays a liner graph");
    //set up panel2 and add it to JTabbedPane
    JPanel panel2 = new JPanel();
    tabbedPane.addTab( "Semi-log", null, graph2, "Displays a semi-log graph");
    add( tabbedPane );
}