Hi list,
the attached slightly modified P2_01 example doesn't work. There seems to be
a problem with big data values. If I don't set the range of heightMap
explicitly, the ScalarMap isn't initialized to the correct min/max data
values (it rounds them somehow). If I set it, it takes minutes before a
window is shown and there's only a point shown instead of a line.
Maybe there's an unintended double to float conversion happening internally?
Timo
--
__.__________
|lmo |homas
/*
VisAD Tutorial
Copyright (C) 2000 Ugo Taddei
*/
// Import needed classes
import visad.*;
import visad.java2d.DisplayImplJ2D;
import java.rmi.RemoteException;
import java.awt.*;
import javax.swing.*;
/**
Enhanced version of program P1_01.
Draw function height = 45 - 5 * time^2
Rename RealTypes and attach units to them.
Draw scales on display to show the RealTypes names.
Run program with java P2_01
*/
public class P2_01{
// Declare variables
// The quantities to be displayed in x- and y-axes
private RealType time, height;
// The function height = f( time ), represented by ( time -> height )
private FunctionType func_t_h;
// Our Data values for time are represented by the set
private Set time_set;
// The Data class FlatField, which will hold time and height data.
// time data are implicitely given by the Set time_set
private FlatField h_vals_ff;
// The DataReference from the data to display
private DataReferenceImpl data_ref;
// The 2D display, and its the maps
private DisplayImpl display;
private ScalarMap timeMap, heightMap;
// The conctructor for our example class
public P2_01 (String []args)
throws RemoteException, VisADException {
// Create the quantities
// time and height are measured in SI seconds and SI meters, respectively
// Use RealType(String name, Unit u, Set set), set is null
time = new RealType("time", SI.second, null);
height = new RealType("height", SI.meter, null);
// Create a FunctionType, that is the class which represents the function
// height = f(time), that is the MathType ( time -> height )
// Use FunctionType(MathType domain, MathType range)
func_t_h = new FunctionType(time, height);
// These are our actual data values
// Create the time_set, with 5 integer values, ranging from 0 to 4.
// That means, that there should be 5 values for height.
// Use Integer1DSet(MathType type, int length)
time_set = new Integer1DSet(time, 5);
// ...the height values
float[][] h_vals = new float[][]{{0.0f, 33.75f, 45.0f, 33.75f, 0.0f,} };
double[][] dh_vals = new double[][]{{917855104, 917855104.25, 917855104.5,
917855104.75, 917855105.0,} };
// double[][] dh_vals2 = new double[][]{{917855104-dh_vals[0][0],
917855104.25-dh_vals[0][0], 917855104.5-dh_vals[0][0],
917855104.75-dh_vals[0][0], 917855105.0-dh_vals[0][0],} };
for (int i=0; i < dh_vals[0].length; i++)
System.out.println(dh_vals[0][i]);
//for (int i=0; i < dh_vals2[0].length; i++)
// System.out.println(dh_vals2[0][i]);
// Create a FlatField, that is the class for the samples
// Use FlatField(FunctionType type, Set domain_set)
h_vals_ff = new FlatField( func_t_h, time_set);
// and put the height values above in it
h_vals_ff.setSamples( dh_vals );
// Create Display and its maps
// A 2D display
display = new DisplayImplJ2D("display1");
// Get display's graphics mode control and draw scales
GraphicsModeControl dispGMC = (GraphicsModeControl)
display.getGraphicsModeControl();
dispGMC.setScaleEnable(true);
// Create the ScalarMaps: quantity time is to be displayed along XAxis
// and height along YAxis
// Use ScalarMap(ScalarType scalar, DisplayRealType display_scalar)
timeMap = new ScalarMap( time, Display.XAxis );
heightMap = new ScalarMap( height, Display.YAxis );
System.out.println("" + dh_vals[0][0] + ", " +
dh_vals[0][dh_vals[0].length-1]);
heightMap.setRange(dh_vals[0][0], dh_vals[0][dh_vals[0].length-1]);
// heightMap.setRange(0, 2) ;
// Add maps to display
display.addMap( timeMap );
display.addMap( heightMap );
// Create a data reference and set the FlatField as our data
data_ref = new DataReferenceImpl("data_ref");
data_ref.setData( h_vals_ff );
// Add reference to display
display.addReference( data_ref );
// Create application window, put display into it
JFrame jframe = new JFrame("My second VisAD application");
jframe.getContentPane().add(display.getComponent());
// Set window size and make it visible
jframe.setSize(300, 300);
jframe.setVisible(true);
}
public static void main(String[] args)
throws RemoteException, VisADException
{
new P2_01(args);
}
} //end of Visad Tutorial Program 2_01
