Reclassify for vector data

11-14-2011 02:54 PM
Status: Implemented
Labels (1)
New Contributor II

A reclassify tool for vector data would be incredibly useful.  Essentially it would act as a way to cement symbology within the attribute table. 

I recently came across the need to take median household income and categorize over 500 records (polygons) into quartiles.  You can easily do this using display symbology, but I wanted to create a field in the attribute table with values of 1, 2, 3, or 4 for each record to denote what quartile that particular record fell into based on the income value.  I wanted this data to be in the attribute table so I could perform further geoprocessing by choosing records by quartile classification.  

To be most useful, this tool would leave the original field data intact and create a new field with the new values.  For my needs, the ability to break the data into ranges is important. 

I was able to get the result I wanted by using the symbology aspect of the Properties for my layer to determine where the quartile breaks should be, jot them down, and then use a python script to calculate a new field.  I told the GIS to take particular ranges of data (quartiles) and assign those records appropriate values (1, 2, 3, 4).  This works, but it is tedious and time-consuming.  If a geogprocessing tool could do the same thing, it would make things much more efficient.  

I would take this a step further.  I have a point and a polygon layer, and I have a need to determine quantiles for a value in the point attribute table by polygon.  I.e., each polygon will have its own quantile breakpoints, and each point will be assigned a (1,2,3,4) based on where its attribute falls within the points in just that polygon. Conceptually this is similar to ZonalStatistics on raster layers, if zonalstats were to provide quantiles.

Basically, we need a "tile" tool. Not to be confused with map tiles. Tile= Quintile, Quantile, Decile, etc. 

We do this within a different analysis software. If esri could get this added, that would be great.

Pick the "tile" method, pick the field(s) to tile by/reclassify, and secondary grouping fields as needed.