Programmatically creating polygon from points on both sides of the international date line?
Accepted Solutions
I've always wondered how to deal with issues with the dateline, then I came across a reference to WGS 1984 (G1762) in the Collector section. This Geographic Coordinate System uses decimal degrees that go North and South past +- 90 degrees and East and West past +- 180 degrees. I created a polygon feature using this system and plotted your coordinates. Those to one side of the dateline were converted to the other side; that is, 130 degrees East became -230 degrees West. Here's my script and results:
import arcpy
dataset = r"C:\Path\To\filegeodatabase.gdb\PolyTest"
sr = arcpy.Describe(dataset).spatialReference
print sr.factoryCode
# 104015
print sr.name
# u'WGS_1984_(G1762)'
# A list of features and coordinate pairs
feature_info = [[[-230, 21],[-205, 21],[-205, 27], [-195, 27],[-195, 43],[-197.083333333333, 45.7],
[-176.566666666667, 50.1333333333333],[-167.816666666667, 51.4],[-160, 53.5],[-153, 56],
[-151.75, 56.8666666666667],[-137, 53.375],[-135, 52.7166666666667],[-133.75, 51],
[-128, 48.3333333333333],[-128, 48.1666666666667],[-126.5, 45],[-126.9, 40.9833333333333],
[-127, 40.8333333333333],[-127, 37.5638888888889],[-126.933333333333, 36.5694444444444],
[-125.833333333333, 35.5],[-124.2, 36],[-123.25, 34.5],[-120.833333333333, 30.75],[-120, 30],
[-120, 3.5],[-145, 3.5],[-155, -5],[-180, -5],[-180, 3.5],[-200, 3.5],[-200, 0],[-219, 0],
[-219, 3.5],[-227, 3.5],[-230, 7]]]
# Open an InsertCursor to insert the new geometry
cursor = arcpy.da.InsertCursor(dataset, ['SHAPE@','Name'])
for feature in feature_info:
# Create a Polygon object based on the array of points
# Append to the list of Polygon objects
polygon = arcpy.Polygon(
arcpy.Array([arcpy.Point(*coords) for coords in feature]))
cursor.insertRow([polygon,'Test1'])
# Delete cursor object
del cursor
I've always wondered how to deal with issues with the dateline, then I came across a reference to WGS 1984 (G1762) in the Collector section. This Geographic Coordinate System uses decimal degrees that go North and South past +- 90 degrees and East and West past +- 180 degrees. I created a polygon feature using this system and plotted your coordinates. Those to one side of the dateline were converted to the other side; that is, 130 degrees East became -230 degrees West. Here's my script and results:
import arcpy
dataset = r"C:\Path\To\filegeodatabase.gdb\PolyTest"
sr = arcpy.Describe(dataset).spatialReference
print sr.factoryCode
# 104015
print sr.name
# u'WGS_1984_(G1762)'
# A list of features and coordinate pairs
feature_info = [[[-230, 21],[-205, 21],[-205, 27], [-195, 27],[-195, 43],[-197.083333333333, 45.7],
[-176.566666666667, 50.1333333333333],[-167.816666666667, 51.4],[-160, 53.5],[-153, 56],
[-151.75, 56.8666666666667],[-137, 53.375],[-135, 52.7166666666667],[-133.75, 51],
[-128, 48.3333333333333],[-128, 48.1666666666667],[-126.5, 45],[-126.9, 40.9833333333333],
[-127, 40.8333333333333],[-127, 37.5638888888889],[-126.933333333333, 36.5694444444444],
[-125.833333333333, 35.5],[-124.2, 36],[-123.25, 34.5],[-120.833333333333, 30.75],[-120, 30],
[-120, 3.5],[-145, 3.5],[-155, -5],[-180, -5],[-180, 3.5],[-200, 3.5],[-200, 0],[-219, 0],
[-219, 3.5],[-227, 3.5],[-230, 7]]]
# Open an InsertCursor to insert the new geometry
cursor = arcpy.da.InsertCursor(dataset, ['SHAPE@','Name'])
for feature in feature_info:
# Create a Polygon object based on the array of points
# Append to the list of Polygon objects
polygon = arcpy.Polygon(
arcpy.Array([arcpy.Point(*coords) for coords in feature]))
cursor.insertRow([polygon,'Test1'])
# Delete cursor object
del cursor
