stud/misc/greedy-points-to-multiline.py

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Python
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2020-03-29 17:38:14 +03:00
#!/usr/bin/env python3
import sys
import rtree
import os
from osgeo import ogr
def main():
infile = sys.argv[1]
driver = ogr.GetDriverByName('gpkg')
inDataSource = driver.Open(infile, 0)
inLayer = inDataSource.GetLayer()
srs = inLayer.GetSpatialRef()
points = get_points(inLayer)
path = greedy_path(points)
outDataSource = driver.CreateDataSource(sys.argv[2])
outLayerName, _ = os.path.splitext(os.path.basename(sys.argv[2]))
outLayer = outDataSource.CreateLayer(outLayerName, srs, geom_type=ogr.wkbLineString)
line = ogr.Geometry(ogr.wkbLineString)
for point in path:
line.AddPoint(point[0], point[1])
outFeature = ogr.Feature(outLayer.GetLayerDefn())
outFeature.SetGeometry(line)
outLayer.CreateFeature(outFeature)
inDataSource.Destroy()
outFeature.Destroy()
outDataSource.Destroy()
def get_points(layer):
points = {}
for (i, pt) in enumerate(layer):
p = pt.GetGeometryRef().GetPoint()
points[i] = (p[0], p[1])
return points
def greedy_path(points):
"Given a dict of points, return a localized short path between them."
idx = rtree.index.Index(interleaved = False)
for (i, pt) in points.items():
idx.insert(i, pt)
def _bounds(_pts):
return (_pts[0], _pts[0], _pts[1], _pts[1])
ret = [0]
idx.delete(0, _bounds(points[0]))
while len(ret) < len(points):
pt = _bounds(points[ret[-1]])
nearest = next(idx.nearest(pt))
ret.append(nearest)
idx.delete(nearest, _bounds(points[nearest]))
ret.append(0)
return [points[point] for point in ret]
if __name__ == '__main__':
main()