vector.py 文件源码

def bbox(coordinates, crs, outname=None, format='ESRI Shapefile', overwrite=True):
    """
    create a bounding box vector object or shapefile from coordinates and coordinate reference system
    coordinates must be provided in a dictionary containing numerical variables with names 'xmin', 'xmax', 'ymin' and 'ymax'
    the coordinate reference system can be in either WKT, EPSG or PROJ4 format
    """
    srs = crsConvert(crs, 'osr')

    ring = ogr.Geometry(ogr.wkbLinearRing)

    ring.AddPoint(coordinates['xmin'], coordinates['ymin'])
    ring.AddPoint(coordinates['xmin'], coordinates['ymax'])
    ring.AddPoint(coordinates['xmax'], coordinates['ymax'])
    ring.AddPoint(coordinates['xmax'], coordinates['ymin'])
    ring.CloseRings()

    geom = ogr.Geometry(ogr.wkbPolygon)
    geom.AddGeometry(ring)

    geom.FlattenTo2D()

    bbox = Vector(driver='Memory')
    bbox.addlayer('bbox', srs, ogr.wkbPolygon)
    bbox.addfield('id', width=4)
    bbox.addfeature(geom, 'id', 1)
    geom.Destroy()
    if outname is None:
        return bbox
    else:
        bbox.write(outname, format, overwrite)