java - Stuck on drawing a set of data points (x,y) -

edited cmilbys suggestion, i'm getting error when adding "replaydata frame.

here replaydata class + paint method

public class replaydata extends jpanel { /**  *   */ private static final long serialversionuid = 1l; private arraylist<point> points;  // create new list of points when ready call redraw() public void replacedata() {     points = new arraylist<point>(); }  public void addpoint(point point) {     points.add(point); }  @override public void paintcomponent(graphics g) {     super.paintcomponent(g);      (point p : points)          g.fillrect(p.x, p.y, 2, 2); }  public void draw() {     repaint();    } } 

and here try call print of records have been retrieved csv

    jbutton button_kmeans = new jbutton("view k-means");     button_kmeans.addactionlistener(new actionlistener() {         public void actionperformed(actionevent arg0) {             kmeans.initialize();             kmeans.kmeancluster();              //for (point p : kmeans.getpoints() )             // slow? data sets going large             point temp = new point();             (int = 0; < kmeans.total_data; i++)             {                            temp.x = (int)trackerdata.getrecordnumber(i).geteyex();                 temp.y = (int)trackerdata.getrecordnumber(i).geteyey();                 replaydata.addpoint(temp); // add points jpanel             }             replaydata.draw();               // how make data shows on 5 seconds, or on 30 etc?         }     }); 

i'm getting errors when adding instance of replaydata frame

at javax.swing.jframe.addimpl(unknown source)

at java.awt.container.add(unknown source)

 private replaydata replaydata;   private void initialize() {      frame = new jframe();     frame.setbounds(100, 100, 1920, 1080);     frame.setdefaultcloseoperation(jframe.exit_on_close);     frame.getcontentpane().setlayout(null);     frame.add(replaydata);  // if comment line program starts fine 

in paintcomponent method should call super.paintcomponent. correct uncomment that.

secondly, replaydata class extends jpanel. because of need use jframe's add method , add instance of class jframe. allow have 1 point though. recommend re-structure class have array of points , not 2 integer variables appears be. example

class replaydate extends jpanel {     private list<point> points;      public replacedata() {         points = new arraylist<point>();     }      public void addpoint(point point) {         points.add(point);     }      @override     public void paintcomponent(graphics g) {         super.paintcomponent(g);          (point p : points)              g.fillrect(point.x, point.y, 2, 2);     }      public void draw() {         repaint();     } }  // in main class private replaydata replaydata;  private void initialize() {     frame = new jframe();     frame.setbounds(100, 100, 1920, 1080);     frame.setdefaultcloseoperation(jframe.exit_on_close);     frame.getcontentpane().setlayout(null);     frame.add(replaydata); // add replay data jframe     jbutton button_kmeans = new jbutton("view k-means");     button_kmeans.addactionlistener(new actionlistener() {     public void actionperformed(actionevent arg0) {         kmeans.initialize();         kmeans.kmeancluster();         (point p : kmeans.getpoints()             replaydata.addpoint(p); // add points jpanel         replaydata.draw();       }  } 

this allow add number of points , draw them all. hope answered question. if still confused leave comment , try explain little more.

edit: few more problems... first: when setting size of jframe, yours seems work since said nothing it, however, i've never used method. future reference can done this.

jframe.getcontentpane().setpreferredsize(new dimension(width, height)); 

as when add replaydata instance jframe, i'm not sure one... copied code compiler , worked fine me. post more code or send me project , can take deeper look.

lastly, you're worried speed. how large datasets? depends on computer. computer has 2.4 ghz intel core i5. since 1 hertz '1/second', assuming did math right, , in ideal world 2.4 billion operations per second. isn't actual case point datasets of ~10,000, notice small delay, seconds.