[mapserver-users] Mapfile Enhancement?

[Paul Ramsey]

Stephen Woodbridge wrote:
> 
> In ArcExplorer there is a feature that allows you to assign class breaks
> to theme properties based on a numeric field attribute and a color ramp.
> Has this be contemplated for 3.6?
> 
> I am generating drivetime polygons that are like contour rings and would
> like to be able to display each ring as a different color. I also
> believe that a few other people have requested a similar feature for
> polygons so they could display different polygons as different colors
> from the same shape file.
> 
> I can work a round it by creating a bunch of class entries.

Perhaps I am misunderstanding, but creating a bunch of class entries
seems like the actual solution and not a work around. e.g.:

LAYER 
  CLASS
    EXPRESSION (([ATTR] > 0) AND ([ATTR] <= 20))
  END
END
LAYER 
  CLASS
    EXPRESSION (([ATTR] > 20) AND ([ATTR] <= 40))
  END
END
LAYER 
  CLASS
    EXPRESSION ([ATTR] > 40)
  END
END

This is a categorical color ramp. If you look in an ArcIMS AXL file, for
example, on a categorical color ramped field, you will see ArcXML
entries which essentially do exactly the above.

-- 
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     | Paul Ramsey
     | Refractions Research
     | Email: pramsey at refractions.net
     | Phone: (250) 885-0632
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