comcen - Computing Centroids in ArcGIS (see Help: Making...

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1 Computing Centroids in ArcGIS (see ‘ Help: Making Field Calculations’) What’s a centroid? § Centroid: a polygon’s mean center which is based on the weighted average of its x and y coordinates; a useful way to summarize the locations of a set of points, particularly when used for comparative analysis. § On the uses of centroids in GIS, see http://www.gsd.harvard.edu/gis /manual/vector/ § Use centroids only if the features are roughly the same size and shape (see, e.g., Mitchell, The ESRI Guide to GIS Analysis , vol. 2). Computing centroids (see ArcMap Help: centroids) : § Inspect the attribute table. § If the attribute table does not already have a column for the ‘X’ and a column for the ‘Y’ coordinates, add these fields (type=double, precision=10, scale=4). § The ‘X’ and ‘Y’ columns are initially populated with 0’s. § Do the following for the ‘X’ column: o Right-click column. o
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This note was uploaded on 07/11/2011 for the course SYA 6356 taught by Professor Staff during the Spring '08 term at University of Florida.

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comcen - Computing Centroids in ArcGIS (see Help: Making...

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