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Hiding "Quantity by Category" Values

June 10 2009 | 0 comments
Categories: ArcGIS Methods, Cartographic Design, Web Maps, Symbology

I have a feature class that contains 8 different types of valves on a utility network. The data was migrated from an old FRAME based system. One of the attributes is symbol scale factor. This by default is set to 1 but can be set to 0.5 0.25 or 0.125. In the old system this would scale down the symbol to "de-clutter" areas with complex asset arrangements.

To replace this in ArcMap I have been looking at using "Quantity by category" to render the symbol at different sizes. The issue here is that the TOC (Table of Contents) becomes long with each valve symbol appearing 4 times at each size.

Is there any way of hiding these repeated symbols from the TOC.

(ArcView/ArcEditor 9.2 SP5 soon to be SP6)

Mapping Center Answer:

Unfortunately the Quantity by Category symbology method does not have any alternatives for the TOC.  The TOC is an inventory of what is drawn on the map, and for complex symbology methods, that can be a bit of a burden. 

Another approach would be to use a series of layers, maybe two or three, that effect a multi-scale approach where the smallest scale layer only shows the proper symbols for valves with scale factor = 1 (via a definition query); all the other valves are either not drawn or drawn as a tiny generic symbol (my experience with utility maps would be to favor not drawing these features).  Maybe this layer shows as is from 1:20,000 down to 1:4,800.  As you zoom in to a larger scale (1:4,800 to 1:2,400) add the values with scale facter = 0.5. Then from 1:2,400 to the largest scales symbolize all the values.  That way you'd get a simpler TOC experience and you could use the scale-visibility feedback to determine which layer to expand (I expect that not all value types are shown at the smallest scales, so having a simpler TOC legend for that layer is desireable).




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