Re: absolute or relative color tables? or ice is always blue

Hi Stuart,

> How do I make a color table or ColorControl so that there
> is a connection between a particular color and a particular data
> value or a range of data values?
> 
> So far as I know a color table in VisAD spans whatever values are displayed.
> Two displays of the same parameter (but different max and mins)
> have differing colors for the same parameter value; very confusing.
> 
> Eventually I want to set up a display so that it knows which colors
> to use for which parameter type as well; if I am plotting a budget I want
> red for less than zero; if I am plotting temperature I want 
> pale blue for less than zero.

This mapping is determined by the low and high values passed
to ScalarMap.setRange(), and by the 'float[][] table' array
passed to BaseColorControl.setTable().  The table values
(length = table[0].length) are distributed evenly over the
(low, high) range.  If an application does not call setRange(),
then the range is determined by the range of values in
displayed data objects.

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