>From: John F Moses <jfmoses@xxxxxxxxxxxxxxxxxxxx>
>Organization: Computer Sciences Corp.
>Keywords: 200008112003.e7BK3tN11187
Hi John-
>i'm trying to simple way to plot a real number at a given lat, lon location
>in the display. i've look at the text plot example, but can't find my way
>through the data types. can someone help me by pointing to an example, or
>code snipet?
Basically, you need to map the MathType of your Real or Text object
to Display.Text.
If you have a RealTuple like (lat, lon, altitude) where the MathTypes
of each are RealType.Latitude, RealType.Longitude, RealType.Altitude,
you could just map lat->Display.YAxis, lon->Display.XAxis and
altitude->Display.Text, add the tuple to your datareference and the
value for altitude should plot at the lat/lon point in your display.
I've attached a file TextPlot.java which will plot a station elevation
at a given lat/lon point. If you pass an arguement to the command line
(any old argument will do), it will plot the station name instead. This
uses NamedLocationTuple in visad.georef which is a tuple of (name, lat,
lon, alt) and is useful for encapsulating a station location.
>being stuck on a friday afternoon, any help would be much appriciated,
My first advice would be to quit and go drink beer, but try out
TextPlot instead as a second option.
Don
*************************************************************
Don Murray UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx P.O. Box 3000
(303) 497-8628 Boulder, CO 80307
*************************************************************
Unidata WWW Server http://www.unidata.ucar.edu/
McIDAS Demonstration Machine http://mcdemo.unidata.ucar.edu/
*************************************************************
import visad.*;
import visad.georef.*;
import visad.java3d.*;
import visad.data.mcidas.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.net.URL;
public class TextPlot
{
public static void main(String[] args)
throws Exception
{
DisplayImpl display =
new DisplayImplJ3D("Station Name Plots",
new TwoDDisplayRendererJ3D());
// turn the box off so it won't be confused with the map lines
display.getDisplayRenderer().setBoxOn(false);
// create the stations
NamedLocationTuple point1 =
new NamedLocationTuple("Denver", 39.8, -104.6, 1656);
NamedLocationTuple point2 =
new NamedLocationTuple("Pueblo", 38.3, -104.5, 1439);
NamedLocationTuple point3 =
new NamedLocationTuple("Grand Junction", 39.2, -108.5, 1439);
// create the ScalarMaps (lat-Y, lon-X, alt/name -> text)
ScalarMap latMap = new ScalarMap(RealType.Latitude, Display.YAxis);
display.addMap(latMap);
ScalarMap lonMap = new ScalarMap(RealType.Longitude, Display.XAxis);
display.addMap(lonMap);
// zoom in over colorado
latMap.setRange(37, 42);
lonMap.setRange(-109, -104);
// set up the mapping to text - use Altitude if no args, otherwise name
ScalarMap textMap;
if (args.length == 0)
{
textMap = new ScalarMap(RealType.Altitude, Display.Text);
}
else
{
textMap =
new ScalarMap(NamedLocationTuple.IDENTIFIER_TYPE, Display.Text);
}
display.addMap(textMap);
// set some attributes of the displayed text
TextControl textControl = (TextControl) textMap.getControl();
textControl.setSize(1.5); // set the text size
textControl.setCenter(true); // center on the LatLonPoint
textControl.setFont(new Font("SansSerif", Font.PLAIN, 18));
// Create a station table with one record for each station
RealType record = new RealType("record"); // Domain type
FunctionType tableType
new FunctionType(record, point1.getType());
Integer1DSet recordSet =
new Integer1DSet(record, 3); // domain the size of the # of stations
FieldImpl stationTable =
new FieldImpl(tableType, recordSet); //make the table
// set the stations in the table
stationTable.setSample(0, point1);
stationTable.setSample(1, point2);
stationTable.setSample(2, point3);
// add the stations to the display
DataReference tableRef = new DataReferenceImpl("stations");
tableRef.setData(stationTable);
display.addReference(tableRef);
// add a map
DataReference mapRef = new DataReferenceImpl("maplines");
try
{
BaseMapAdapter bma =
new BaseMapAdapter(
new URL("ftp://www.ssec.wisc.edu/pub/visad-2.0/OUTLUSAM";));
mapRef.setData(bma.getData());
display.addReference(mapRef);
}
catch (Exception exp) {} // don't add to display if we can't get map
// something to display it with
JFrame frame = new JFrame("Text Display");
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e)
{ System.exit(0); }
});
frame.getContentPane().add(display.getComponent());
frame.pack();
frame.setSize(400,400);
frame.show();
}
}
