Re: Simple Gridded2D&3DSets

• To: "William L. Hibbard" <WHIBBARD@xxxxxxxxxxxxx>
• Subject: Re: Simple Gridded2D&3DSets
• From: Mohamad Ijadi <mohamad@xxxxxxxx>
• Date: Tue, 16 Feb 1999 17:08:26 -0700

Thanks Bill.  I am getting to understand VisAD concepts better as I find
time to check it out.  So please bear with me:).  The surface examples
and the FlatField.makeFieild() methods were helpful and I am able to
display 2D surfaces for geologic layers (well, computed).  It looks like
a FlatField with a (x,y)-to-depth FunctionType and a Linear2DSet can do
the job for my data.   Fancier FunctionTypes and ScalarMaps for color
coding depth values are cool too.  Hopefully I can use VisAD for more
extensive 3D visualization and volume rendering of oil & gas reservoirs,
gelogical features, etc.

For now, I am not sure if I load the surface data arrays correctly (and
not being a geologist, I can't tell from the pictures:).  My data comes
in three columns (x, y, depth) with x varying first and then y,
something like:

x y depth
1 1 some value
2 1 ...
3 1 ...
1 2 ...
2 2 ...
3 2 ...

Linear2DSet can be good for this; I know the xy grid bounds and steps.
To load the FlatField sample set as I parse this file I do:

for (int y=0; y < yGridSize.intValue(); y++) {
  for (int x=0; x < xGridSize.intValue(); x++) {
    line = data.readLine();
    tokens = new StringTokenizer(line);
    // skip over x & y and get  depth
    tokens.nextToken();  tokens.nextToken();
    dataArr[0][x + xGridSize.intValue()*y]
          Float.valueOf(tokens.nextToken()).doubleValue();
  }
}

image.setSamples(dataArr);

Does this load dataArr correctly for visad?  Thanks,

-- mohamad
LANL

"William L. Hibbard" wrote:

> Hi Mohamad,
>
> Most of the examples/TestNN.java demos (where 00 <= NN <= 54)
> use FlatFields whose domain sets are Linear1DSet, Linear2DSet
> or Linear3DSet, which extend Gridded1DSet, Gridded2DSet and
> Gridded3DSet.  These programs demonstrate many different ways
> of displaying data.  These FlatFields are constructed by calls
> to FlatField.makeField.  When its last parameter is false,
> makeField returns a FlatField whose domain Set is Linear.
> The dimension is the dimension of the domain type of the
> FunctionType that is the first parameter of makeField.
>
> Cheers,
> Bill
>
> ----------------------------------------------------------
> Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
> whibbard@xxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738
> http://www.ssec.wisc.edu/~billh/vis.html
>

• References:
  • p.s. Re: Simple Gridded2D&3DSets
    • From: William L. Hibbard