3 replies to this topic

[gorillamap]

I am searching for the best way to create an automated legend for zoning data.

The actual zoning that polygons can have may be simple (A – Extensive Agriculture) or complex (A FPS GH KRC – Extensive Agriculture, Floodplain Secondary Combining, Geologic Hazard Combining, Kern River Corridor Combining). Displaying the latter in an ArcGIS legend takes more room on the page than I can typically spare. In the old hand-drafting days, the legend was broken down by each visible zoning component, i.e. the polygon would be labeled ‘A FPS GH KRC,’ but the legend would read ‘A – Extensive Agriculture’ followed by a separate line ‘FPS – Floodplain Secondary Combining,’ etc., and the combining elements would only be listed once.

I’m looking for any suggestions you may have to keep the legend as simple as possible while still automatically creating it from a table or shapefile. I want to do this automatically since I will have non-cartographers making maps.

I’ve attached two JPEGs as examples. Thanks in advance and please let me know if you need any clarification.

Attached Files

•  AutoLeg.jpg   255.96K   74 downloads
•  HandLeg.jpg   160.45K   65 downloads

[Martin Gamache]

It may be that you need to create a new column in your data that is an abbreviated class name and that the legend label refers to this name while maybe the polygon labels on the maps use a more complete label. Another solution may also be that you have one legend which is very complete with subclasses and an explanation of abbreviations but that stays the same for all maps regardless of whether or not all classes appear on that map and is added as a raster image. That eliminates the need to redesign every legend. Another solution is to have a very simple legend on the maps but having a more complete legend available seperately.

There is likely a scripting solution that can solve the issue as well but that requires someone with some expertise in writing said script. The design problem is another issue and has to balance available space vs number of legend elements and font sizes and legend placement. My experience is that it is very complicated to fully automate all these things and still end up with good looking product. If your zoning maps are on a steady grid all the same scale and size it is easier.

I redesigned a zoning atlas a couple years ago (BRA Zoning Maps) and legend elements were a huge headache (this one for example), we ended-up hand editing all the legends because of their complexity. So don't discount the hand placing "old days" they are still the best. Consider zoning maps one of your agency's most important mapping products, IMO it's not the place to cut corners and try to get away with the least amount of work and still expect a high quality product. If you need to edit the legends manually, create a template and train your "non cartograhers" to make custom legends to the template using the auto created legend as a starting point. A well designed grid with guidelines should be very to use to do something like this.

[DaveB]

Well, it's not automatic, but you could use descriptions for the legend text. Maybe use the abbreviaition as the legend class label and enter the longer text as class descriptions with line breaks to wrap the text.
For more information on creating and using descriptions search for "descriptions" in the ESRI Support site, and be sure to check the box for the appropriate product to narrow the search.
If you can write code or have someone who can you could probably code a way to populate the description to make this more automated.

[frax]

Maybe I am not getting it, but this shouldn't be any problem in ArcGIS, it is very easy to join and have look up tables, or manipulate attribute data using SQL (In access for geodatabases, in RDBMS for SDE or in excel for shape-files).

It is also possible to have scripting in the label display.

One trick to have the legend and the data displaying different titles could be to create a "dummy layer" with nothing displaying in the map view that is just used for the legend. E.g. the data used for the display is not displaying any legend, just add the same data again and make all the polys all transparent and use that for the legend.