A collection of various GIS related links, information and other GIS blogs.

Sunday, August 24, 2008

Mapping Center : "Angeles River, Los"

[ From the ESRI Mapping Center ]

"Angeles River, Los"

Making maps with data that were never intended for mapping has it's challenges. One of them is trying to use the names from GNIS (Geographic Names Information System) (U.S. Board on Geographic Names).  Even when someone has gone to the effort of assigning these names to GIS features, the way the names are formatted can create problems.  In the case of the GNIS, the names were formatted for an old-style (i.e., pre-modern search engine) alphabetical index that you could visually scan like a gazetteer in an atlas.  The result is that there are entries like "Great Salt Lake, The" or "Grande, Rio" which need reformatting in order to look correct on a map. 

As a general rule if a name in the GNIS, or data compiled with GNIS names, has a comma, then it needs to be edited.  Rather than manually edit each of those names, I felt it would be handy to have something to automate that work. So I wrote a field calculator statement that you can download to do the job.  It gets the portion of the name after the comma and moves it to the front of the string, and removes the comma.

Be careful, first select by attribute all the features that have a comma in the name; minimally it will save time:

"GNIS_Name" LIKE '%,%'    (this is using the correct syntax for file geodatabase format)

Once the features are selected, verify that you have no unexpected commas.  Then while that selection is still applied, calculate the field by loading the FlipAroundComma.cal file that is inside the ZIP file in the hyperlink above.

The result will help your maps look more professional. 

Mapping Center : "Angeles River, Los"

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