Re: user-defined color tables; cross sections

• To: Stuart Wier <wier@xxxxxxxxxxxxxxxx>
• Subject: Re: user-defined color tables; cross sections
• From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>
• Date: Fri, 21 Jul 2000 13:09:06 -0500

Si Stu,

> First, please remind me how to create a set of pre-defined
> color tables, and apply them to a display. I found this
> much in the mail list archive:
> 
> "you could try computing a color table:
> 
>   ColorControl control = (ColorControl) cmap.getControl();
>   float[][] table = new float[3][256];
>   for (int j=0; j<256; j++) {
>     table[0][j] = ... // j-th red
>     table[1][j] = ... // j-th green
>     table[2][j] = ... // j-th blue
>   }
>   control.setTable(table);"
> 
> then how do I use a ColorControl?

  ScalarMap rgbMap = new ScalarMap(yourRealType, Display.RGB);
  display.addMap(rgbMap);
  ColorControl control = (ColorControl) rgbMap.getControl();

> And is there a VisAD example that shows how to
> create a cross section (2D display) for a plane
> across a 3D display?  Are there pre-defined cross-sections
> like the old drafting elevation-plan-section, or is the
> cross section on an arbitrary plane?

There is no example in the distribution.  You create a
Gridded2DSet with manifold dimension = 2 that defines a
grid of points on your plane slice, then resample() your
FlatField to that Gridded2DSet, then display the FlatField
returned by resample().  I think Doug Lindholm has done it
so you might talk to him - I know you guys work across the
street from each other ;)

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

• Follow-Ups:
  • Re: user-defined color tables; cross sections
    • From: Doug Lindholm
  • Re: user-defined color tables; cross sections
    • From: Doug Lindholm

• References:
  • freehand curve drawing, rubber band boxes, and fonts
    • From: Bill Hibbard
  • user-defined color tables; cross sections
    • From: Stuart Wier