Question

我试图通过缓冲点（SEPTA地铁站[下方]）和计算“事件数”进行相当简单的分析。（也指出）位于缓冲区内。那就是它。

我已经在网上看了一些，但我找不到具体的内容。也许这很容易，没人需要问。我真的可以使用一些帮助。

我能够修复代码并为点创建缓冲区，但我似乎无法计算缓冲区内的点数。此外，＆＃39;事件＆＃39;我正在使用的点集，所以我用“农民市场”转换它。以下是我到目前为止所做的事情。再一次，我只需要计算点数。

from osgeo import ogr

septaclip = ogr.Open(r'/home/user/Downloads/SEPTAclip.shp')
septalyr = septaclip.GetLayer(0)
citylimits = ogr.Open(r'/home/user/Downloads/City_Limits.shp')
citylyr = citylimits.GetLayer(0)
crimestat = ogr.Open(r'/home/user/Downloads/Farmers_Markets.shp')
crimelyr = crimestat.GetLayer(0)

memory_driver = ogr.GetDriverByName('Memory')
memory_ds = memory_driver.CreateDataSource('Temp')
buff_lyr = memory_ds.CreateLayer('Buffer')
buff_feat = ogr.Feature(buff_lyr.GetLayerDefn())

multipoly = ogr.Geometry(ogr.wkbMultiPolygon)
for septafeat in septalyr:             
    buff_geo = septafeat.geometry().Buffer(3000) 
    multipoly.AddGeometry(buff_geo)
#multipoly = (multipoly.UnionCascaded())  

for crimefeat in crimelyr:
    buffcrime = crimefeat.geometry().Intersection(multipoly)

Answer 1

尝试这个来计算交叉点后的点数：

count = 0
for crimefeat in crimelyr:
    if not crimefeat.geometry().Intersection(multipoly).IsEmpty():
        count += 1

或使用OGR的功能：

crime_multipoint = ogr.Geometry(ogr.wkbMultiPoint)
for crimefeat in crimelyr:
    crime_multipoint.AddGeometry(crimefeat.geometry())
crime_multipoint.Intersection(multipoly).GetGeometryCount()

Python（可能是Shapely）来创建缓冲区和计数点

1 个答案: