Re: Question: Visualization of Function with Domain Dimension > 2

• To: visad-list@xxxxxxxxxxxxx
• Subject: Re: Question: Visualization of Function with Domain Dimension > 2
• From: "From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>" <billh@xxxxxxxxxxxxx>
• Date: Wed, 19 May 1999 16:15:39 -0500 (CDT)

Hi Mike,
 
Try something like this:
 
  float zplane = ... // the z value of the plane
  // first compute the x and y extents of the data
  // to get bounds for a Set in the z plane
  float xmin = Float.MAX_VALUE;
  float xmax = Float.MIN_VALUE;
  float ymin = Float.MAX_VALUE;
  float ymax = Float.MIN_VALUE;
  for (int i=0; i<MAX; i++) {
    if (threeDsamples[0][i] < xmin) xmin = threeDsamples[0][i];
    if (threeDsamples[0][i] > xmax) xmax = threeDsamples[0][i];
    if (threeDsamples[1][i] < ymin) ymin = threeDsamples[1][i];
    if (threeDsamples[1][i] > ymax) ymax = threeDsamples[1][i];
  }
  // create the samples for the Set
  float[][] plane = new float[3][NUM * NUM];
  int k = 0;
  for (int i=0; i<NUM; i++) {
    for (int j=0; j<NUM; j++) {
      plane[0][k] = xmin + (xmax - xmin) * i / (NUM - 1.0f);
      plane[1][k] = ymin + (ymax - ymin) * j / (NUM - 1.0f);
      plane[2][k++] = zplane;
    }
  }
  // construct a Gridded3DSet with manifold dimension = 2
  // whose N * N samples lie on a plane at z = zplane
  Gridded3DSet plane_set
    new Gridded3DSet(grid_type.getDomain(), plane, NUM, NUM);
  // resample the FlatField to plane_set
  FlatField fplane = f.reample(plane_set, Data.WEIGHTED_AVERAGE,
                               Data.NO_ERRORS);
 
  // now construct a Gridded2DSet in purely (x, y)
  float[][] plane2 =  {plane[0], plane[1]};
  RealTupleType xy = new RealTupleType(x, y};
  Gridded2DSet xy_set = new Gridded2DSet(xy, plane2,  NUM, NUM);
  FuntionType xy_grid_type = new FunctionType(xy, w);
  FlatField fxy = new FlatField(xy_grid_type, xy_set);
  // copy the range values from fplane to fxy
  fxy.setSamples(fplane.getValues());
 
  // now display fxy with MathType ((x, y) -> w)
  // and resampling values from the original FlatField on
  // the plane z = zplane
  x.setData(fxy); // instead of setData(f);
 
I haven't compiled or run this code, so there may be a few bugs but
the basic idea is right, I think.  Please let me know if you have
problems.

Cheers,
Bill
----------------------------------------------------------
Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
http://www.ssec.wisc.edu/~billh/vis.html