zonalstats.py 文件源码

def _check_src(self, src):
        """ Basic check of source elements (sequence of points or polygons).

            - array cast of source elements
            - create ogr_src datasource/layer holding src points/polygons
            - transforming source grid points/polygons to ogr.geometries
              on ogr.layer
        """
        ogr_src = io.gdal_create_dataset('Memory', 'out',
                                         gdal_type=gdal.OF_VECTOR)

        try:
            # is it ESRI Shapefile?
            ds_in, tmp_lyr = io.open_shape(src, driver=ogr.
                                           GetDriverByName('ESRI Shapefile'))
            ogr_src_lyr = ogr_src.CopyLayer(tmp_lyr, self._name)
            if self._srs is None:
                self._srs = ogr_src_lyr.GetSpatialRef()
        except IOError:
            # no ESRI shape file
            raise
        # all failed? then it should be sequence or numpy array
        except RuntimeError:
            src = np.array(src)
            # create memory datasource, layer and create features
            if src.ndim == 2:
                geom_type = ogr.wkbPoint
            # no Polygons, just Points
            else:
                geom_type = ogr.wkbPolygon
            fields = [('index', ogr.OFTInteger)]
            georef.ogr_create_layer(ogr_src, self._name, srs=self._srs,
                                    geom_type=geom_type, fields=fields)
            georef.ogr_add_feature(ogr_src, src, name=self._name)

        return ogr_src