dmahr

Can't create polygon geometry smaller than 0.003 degrees?

Discussion created by dmahr on Aug 31, 2011
Latest reply on Aug 31, 2011 by dmahr
Hi all--

I have a need to automate the creation of many evenly spaced square polygons, each 0.0021 decimal degrees in size.  I did it in ArcPython using an array of Point objects.  When I make each side of a square 0.0035 decimal degrees, everything works fine.  When I make each size 0.0025 (or less) nothing shows up.  This variable is the "diff" variable in my code below.  Doing "Zoom to layer" zooms out to full extent of the coordinate system. 

Any ideas why I can't make polygons features smaller?  I thought to check the vertices of the output, but I don't have ArcInfo so I can't use Feature Vertices to Points.

Here's my code:
##### Import modules
import arcpy
import os
import datetime

##### Set home directory and workspace

HomeDir = "C:\\Desktop\\testing\\"
arcpy.env.workspace = HomeDir

##### Overwrite
arcpy.env.overwriteOutput = True

##### Variables for Input Files
SpatialReference = "WGS_1984.prj"

##### Variables for Output Files
output_polygon_shp = "Output_Polygon.shp"

#Dimension of polygon side
diff = float(0.0025)

#Empty feature list
featureList = []
#Point object
point = arcpy.Point()
#Array object
array = arcpy.Array()


#Upper left
point.Y = -7
point.X = -57
array.add(point)

#Lower left
point.Y = -7 - diff
point.X = -57
array.add(point)

#Lower right
point.Y = -7 - diff
point.X = -57 + diff
array.add(point)

#Upper right
point.Y = -7
point.X = -57 + diff
array.add(point)

#Closing point
array.add(array.getObject(0))


#Create polygon
polygon = arcpy.Polygon(array)

#Clear array
array.removeAll()

#Add polygon
featureList.append(polygon)

#Create shapefile
arcpy.CopyFeatures_management(featureList, output_polygon_shp)

#Define projection
arcpy.DefineProjection_management(output_polygon_shp, SpatialReference)

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