The only possibility that occurs to me is that the method
plot.export(out_image) is getting executed before the last
plot.addPoint() is executed. To test this theory,
try placing at least plot.export(out_image) in the event
thread, using code like this:
Runnable doExport = new Runnable() {
public void run() {
plot.export(out_image);
}
};
try {
SwingUtilities.invokeLater(doExport);
} catch (InterruptedException ex) {
// Ignore InterruptedException.
// Other exceptions should not occur.
}
To do this, out_image will have to be declared "final".
The reason for this is that add_point's action is deferred to
execute in the event thread. It is arguable that probably export()
should be as well...
Edward
At 12:23 PM 7/1/2002 +0200, Luigi Paioro wrote:
>Hello to everybody!
>
>I'm using the PtPlot classes to plot some dynamic charts that are
>elaborated by a Java Servlet. I don't know why, but if I plot more time
>the same dataset (and also not the same!), my Plot losts some points...
>but not always the same number... it seems that the addPoint(...) method
>fails over a random number of points added.
>
>My plot cames from a POST method on my servlet that make a query on a
>database and plot the result adding the values of the two columns selected:
>
>Plot plot = new Plot();
>
>plot.setButtons(false);
>plot.setConnected(false);
>plot.setImpulses(false);
>plot.setBars(false);
>plot.setMarksStyle("various");
>plot.setBackground(Color.white);
>
>Statement stmt = null;
>ResultSet result = null;
>
>stmt = Cnn.createStatement();
>result = stmt.executeQuery(sql);
>
>while (result.next()) {
> int i = result.findColumn(fieldx1);
> int j = result.findColumn(fieldy1);
> String sx = result.getString(i);
> String sy = result.getString(j);
> double x = (Double.valueOf(sx)).doubleValue();
> double y = (Double.valueOf(sy)).doubleValue();
> plot.addPoint(0, x, y, false);
>}
>
>fieldx1 and fieldy1 come from the HTML form... they are just the column
>name, and the sql string is the SQL statement.
>
>In the end I send an EPS to the browser OutputStream:
>
>OutputStream out_image = response.getOutputStream();
>response.setContentType("application/postscript");
>plot.export(out_image);
>
>It's a simple code, but if I run it more times, it losts some points... it
>seems that the servlet cannot plot more points than a break point that
>variates each time. Note that it is not a SQL trouble: the query works fine!
>
>What about this?
>
>Thank, Luigi.
>
>--
>
>Dr. Luigi Paioro
>
>C.N.R. - I.A.S.F.
>
>Consiglio Nazionale delle Ricerche
>
>Istituto di Astrofisica Spaziale e
>Fisica Cosmica "G.P.S. Occhialini"
>
>via Bassini 15, I-20133 Milano, Italy
>
>e.mail: [EMAIL PROTECTED]
>phone: +39 02 23699349
>fax: +39 02 2666017
>
>
>----------------------------------------------------------------------------
>Posted to the ptolemy-hackers mailing list. Please send administrative
>mail for this list to: [EMAIL PROTECTED]
------------
Edward A. Lee, Professor
518 Cory Hall, UC Berkeley, Berkeley, CA 94720
phone: 510-642-0455, fax: 510-642-2739
[EMAIL PROTECTED], http://ptolemy.eecs.berkeley.edu/~eal
----------------------------------------------------------------------------
Posted to the ptolemy-hackers mailing list. Please send administrative
mail for this list to: [EMAIL PROTECTED]
