/*-/* Applet1.java: plots f(x) -*/*/
import java.applet.Applet;         /*++-add Applet classes-++*/
import java.awt.*;                /*++-Abstract Windows Toolkit-++*/
public class Applet1 extends Applet        /*++- class definition -++*/
{   double mx, my, bx, by;  /*++- class variables for all methods -++*/
    /*-//paint method. Execution begins here (no main) 
    g: Graphics context (graph object) passed by browser-*/
    public void paint(Graphics g) 
 {  double x, y;          /*++- //world coordinates -++*/
    int gOldX, gOldY, gNewX, gNewY;    /*++-//window coordinates-++*/
    g.drawString("In Applet1.class, f(x) vs x", 40, 40); /*++-//Title-++*/
    System.out.println("In Applet1.class, about to draw graph");
    world2win(0.0,1.0,1.0,0.0); /*++-//determine mapping params-++*/
    /*-//Step through the points-*/
    x = 0.; /*++-//first point-++*/
    y = f(x); /*++-//f(x) = function to plot-++*/
    gOldX = (int)(mx*x+bx); /*++-//convert to window coords-++*/
    gOldY = (int)(my*y+by);   
    for (x = 0.01; x <= 1.0; x = x+0.01) {
        y = f(x);
        gNewX = (int)(mx*x+bx); /*++-//convert to window coords-++*/
        gNewY = (int)(my*y+by);  
        System.out.println(" " +x+" , y= "+y+" ");
        g.drawLine(gOldX, gOldY, gNewX, gNewY); /*++-//line segment-++*/
        gOldX = gNewX; /*++-//new point becomes old-++*/
        gOldY = gNewY;  }
 }  
    /*-// function f(x) to plot -*/
    public static double f(double x) 
    { return x/2. + x*0.2*Math.sin(33*x); }
    /*-// method worl2win computes mapping parameters-*/
    void world2win(double xl,double yt,double xr,double yb) 
    {  /*-//(x,y) = world (double) ->  window (int)-*/
    /*-//x__win = m_x * x + b_x,     y_win = m_y * y + b_y-*/      
    double maxx=350, maxy=250, rm, lm, tm, bm;
    lm = 0.1 * maxX; /*++-//margins, all around-++*/
    rm = 0.9 * maxX;         
    bm = 0.9 * maxY;             
    tm = 0.1 * maxY;         
    mx = (lm-rm)/(xl-xr); /*++-//mapping params wrt margins-++*/
    bx = (xl*rm-xr*lm) / (xl-xr);
    my = (tm-bm) / (yt-yb);
    by = (yb*tm-yt*bm) / (yb-yt); }    
}