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geometry.rst

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Geometry

Create a Point

from osgeo import ogr
point = ogr.Geometry(ogr.wkbPoint)
point.AddPoint(1198054.34, 648493.09)
print point.ExportToWkt()

Create a LineString

from osgeo import ogr
line = ogr.Geometry(ogr.wkbLineString)
line.AddPoint(1116651.439379124, 637392.6969887456)
line.AddPoint(1188804.0108498496, 652655.7409537067)
line.AddPoint(1226730.3625203592, 634155.0816022386)
line.AddPoint(1281307.30760719, 636467.6640211721)
print line.ExportToWkt()

Create a Polygon

from osgeo import ogr

# Create ring
ring = ogr.Geometry(ogr.wkbLinearRing)
ring.AddPoint(1179091.1646903288, 712782.8838459781)
ring.AddPoint(1161053.0218226474, 667456.2684348812)
ring.AddPoint(1214704.933941905, 641092.8288590391)
ring.AddPoint(1228580.428455506, 682719.3123998424)
ring.AddPoint(1218405.0658121984, 721108.1805541387)
ring.AddPoint(1179091.1646903288, 712782.8838459781)

# Create polygon
poly = ogr.Geometry(ogr.wkbPolygon)
poly.AddGeometry(ring)

print poly.ExportToWkt()

Create a Polygon with holes

from osgeo import ogr

# Create outer ring
outRing = ogr.Geometry(ogr.wkbLinearRing)
outRing.AddPoint(1154115.274565847, 686419.4442701361)
outRing.AddPoint(1154115.274565847, 653118.2574374934)
outRing.AddPoint(1165678.1866605144, 653118.2574374934)
outRing.AddPoint(1165678.1866605144, 686419.4442701361)
outRing.AddPoint(1154115.274565847, 686419.4442701361)

# Create inner ring
innerRing = ogr.Geometry(ogr.wkbLinearRing)
innerRing.AddPoint(1149490.1097279799, 691044.6091080031)
innerRing.AddPoint(1149490.1097279799, 648030.5761158396)
innerRing.AddPoint(1191579.1097525698, 648030.5761158396)
innerRing.AddPoint(1191579.1097525698, 691044.6091080031)
innerRing.AddPoint(1149490.1097279799, 691044.6091080031)

# Create polygon
poly = ogr.Geometry(ogr.wkbPolygon)
poly.AddGeometry(outRing)
poly.AddGeometry(innerRing)

print poly.ExportToWkt()

Create a MultiPoint

from osgeo import ogr

multipoint = ogr.Geometry(ogr.wkbMultiPoint)

point1 = ogr.Geometry(ogr.wkbPoint)
point1.AddPoint(1251243.7361610543, 598078.7958668759)
multipoint.AddGeometry(point1)

point2 = ogr.Geometry(ogr.wkbPoint)
point2.AddPoint(1240605.8570339603, 601778.9277371694)
multipoint.AddGeometry(point2)

point3 = ogr.Geometry(ogr.wkbPoint)
point3.AddPoint(1250318.7031934808, 606404.0925750365)
multipoint.AddGeometry(point3)

print multipoint.ExportToWkt()

Create a MultiLineString

from osgeo import ogr

multiline = ogr.Geometry(ogr.wkbMultiLineString)

line1 = ogr.Geometry(ogr.wkbLineString)
line1.AddPoint(1214242.4174581182, 617041.9717021306)
line1.AddPoint(1234593.142744733, 629529.9167643716)
multiline.AddGeometry(line1)

line1 = ogr.Geometry(ogr.wkbLineString)
line1.AddPoint(1184641.3624957693, 626754.8178616514)
line1.AddPoint(1219792.6152635587, 606866.6090588232)
multiline.AddGeometry(line1)

print multiline.ExportToWkt()

Create a MultiPolygon

from osgeo import ogr

multipolygon = ogr.Geometry(ogr.wkbMultiPolygon)

# Create ring #1
ring1 = ogr.Geometry(ogr.wkbLinearRing)
ring1.AddPoint(1204067.0548148106, 634617.5980860253)
ring1.AddPoint(1204067.0548148106, 620742.1035724243)
ring1.AddPoint(1215167.4504256917, 620742.1035724243)
ring1.AddPoint(1215167.4504256917, 634617.5980860253)
ring1.AddPoint(1204067.0548148106, 634617.5980860253)

# Create polygon #1
poly1 = ogr.Geometry(ogr.wkbPolygon)
poly1.AddGeometry(ring1)
multipolygon.AddGeometry(poly1)

# Create ring #2
ring2 = ogr.Geometry(ogr.wkbLinearRing)
ring2.AddPoint(1179553.6811741155, 647105.5431482664)
ring2.AddPoint(1179553.6811741155, 626292.3013778647)
ring2.AddPoint(1194354.20865529, 626292.3013778647)
ring2.AddPoint(1194354.20865529, 647105.5431482664)
ring2.AddPoint(1179553.6811741155, 647105.5431482664)

# Create polygon #2
poly2 = ogr.Geometry(ogr.wkbPolygon)
poly2.AddGeometry(ring2)
multipolygon.AddGeometry(poly2)

print multipolygon.ExportToWkt()

Create Geometry from WKT

from osgeo import ogr

wkt = "POINT (1120351.5712494177 741921.4223245403)"
point = ogr.CreateGeometryFromWkt(wkt)
print "%d,%d" % (point.GetX(), point.GetY())

Create Geometry from GeoJSON

from osgeo import ogr

geojson = """{"type":"Point","coordinates":[108420.33,753808.59]}"""
point = ogr.CreateGeometryFromJson(geojson)
print "%d,%d" % (point.GetX(), point.GetY())

Create Geometry from GML

from osgeo import ogr

gml = """<gml:Point xmlns:gml="http://www.opengis.net/gml"><gml:coordinates>108420.33,753808.59</gml:coordinates></gml:Point>"""
point = ogr.CreateGeometryFromGML(gml)
print "%d,%d" % (point.GetX(), point.GetY())

Create Geometry from WKB

from osgeo import ogr
from base64 import b64decode

wkb = b64decode("AIAAAAFBMkfmVwo9cUEjylouFHrhAAAAAAAAAAA=")
point = ogr.CreateGeometryFromWkb(wkb)
print "%d,%d" % (point.GetX(), point.GetY())

Count Points in a Geometry

from osgeo import ogr

wkt = "LINESTRING (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)"
geom = ogr.CreateGeometryFromWkt(wkt)
print "Geometry has %i points" % (geom.GetPointCount())

Count Geometries in a Geometry

from osgeo import ogr

wkt = "MULTIPOINT (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)"
geom = ogr.CreateGeometryFromWkt(wkt)
print "Geometry has %i geometries" % (geom.GetGeometryCount())

Iterate over Geometries in a Geometry

from osgeo import ogr

wkt = "MULTIPOINT (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)"
geom = ogr.CreateGeometryFromWkt(wkt)
for i in range(0, geom.GetGeometryCount()):
    g = geom.GetGeometryRef(i)
    print "%i). %s" %(i, g.ExportToWkt())

Iterate over Points in a Geometry

from osgeo import ogr

wkt = "LINESTRING (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)"
geom = ogr.CreateGeometryFromWkt(wkt)
for i in range(0, geom.GetPointCount()):
    # GetPoint returns a tuple not a Geometry
    pt = geom.GetPoint(i)
    print "%i). POINT (%d %d)" %(i, pt[0], pt[1])

Buffer a Geometry

from osgeo import ogr

wkt = "POINT (1198054.34 648493.09)"
pt = ogr.CreateGeometryFromWkt(wkt)
bufferDistance = 500
poly = pt.Buffer(bufferDistance)
print "%s buffered by %d is %s" % (pt.ExportToWkt(), bufferDistance, poly.ExportToWkt())

Calculate Envelope of a Geometry

from osgeo import ogr

wkt = "LINESTRING (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)"
geom = ogr.CreateGeometryFromWkt(wkt)
# Get Evenlope return a tuple (minX, maxX, minY, maxY)
env = geom.GetEnvelope()
print "minX: %d, minY: %d, maxX: %d, maxY: %d" %(env[0],env[2],env[1],env[3])

Calculate the Area of a Geometry

from osgeo import ogr

wkt = "POLYGON ((1162440.5712740074 672081.4332727483, 1162440.5712740074 647105.5431482664, 1195279.2416228633 647105.5431482664, 1195279.2416228633 672081.4332727483, 1162440.5712740074 672081.4332727483))"
poly = ogr.CreateGeometryFromWkt(wkt)
print "Area = %d" % poly.GetArea()

Calculate the Length of a Geometry

from osgeo import ogr

wkt = "LINESTRING (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)"
geom = ogr.CreateGeometryFromWkt(wkt)
print "Length = %d" % geom.Length()

Get the geometry type (as a string) from a Geometry

from osgeo import ogr

wkts = [
    "POINT (1198054.34 648493.09)",
    "LINESTRING (1181866.263593049 615654.4222507705, 1205917.1207499576 623979.7189589312, 1227192.8790041457 643405.4112779726, 1224880.2965852122 665143.6860159477)",
    "POLYGON ((1162440.5712740074 672081.4332727483, 1162440.5712740074 647105.5431482664, 1195279.2416228633 647105.5431482664, 1195279.2416228633 672081.4332727483, 1162440.5712740074 672081.4332727483))"
]

for wkt in wkts:
    geom = ogr.CreateGeometryFromWkt(wkt)
    print geom.GetGeometryName()

Calculate intersection between two Geometry

from osgeo import ogr

wkt1 = "POLYGON ((1208064.271243039 624154.6783778917, 1208064.271243039 601260.9785661874, 1231345.9998651114 601260.9785661874, 1231345.9998651114 624154.6783778917, 1208064.271243039 624154.6783778917))"
wkt2 = "POLYGON ((1199915.6662253144 633079.3410163528, 1199915.6662253144 614453.958118695, 1219317.1067437078 614453.958118695, 1219317.1067437078 633079.3410163528, 1199915.6662253144 633079.3410163528)))"

poly1 = ogr.CreateGeometryFromWkt(wkt1)
poly2 = ogr.CreateGeometryFromWkt(wkt2)

intersection = poly1.Intersection(poly2)

print intersection.ExportToWkt()