Source code for trackintel.preprocessing.filter

import geopandas as gpd

[docs]def spatial_filter(source, areas, method="within", re_project=False): """ Filter staypoints, locations or triplegs with a geo extent. Parameters ---------- source : GeoDataFrame (as trackintel datamodels) The source feature to perform the spatial filtering areas : GeoDataFrame The areas used to perform the spatial filtering. Note, you can have multiple Polygons and it will return all the features intersect with ANY of those geometries. method : {'within', 'intersects', 'crosses'} The method to filter the 'source' GeoDataFrame - 'within' : return instances in 'source' where no points of these instances lies in the \ exterior of the 'areas' and at least one point of the interior of these instances lies \ in the interior of 'areas'. - 'intersects': return instances in 'source' where the boundary or interior of these instances \ intersect in any way with those of the 'areas' - 'crosses' : return instances in 'source' where the interior of these instances intersects \ the interior of the 'areas' but does not contain it, and the dimension of the intersection \ is less than the dimension of the one of the 'areas'. re_project : bool, default False If this is set to True, the 'source' will be projected to the coordinate reference system of 'areas' Returns ------- ret_gdf: GeoDataFrame (as trackintel datamodels) A new GeoDataFrame containing the features after the spatial filtering. Examples -------- >>> sp.as_staypoints.spatial_filter(areas, method="within", re_project=False) """ gdf = source.copy() if re_project: init_crs = gdf = gdf.to_crs( # build spatial index for pre filtering source_sindex = gdf.sindex possible_matches_index = [] for other in areas.itertuples(): bounds = other.geometry.bounds c = list(source_sindex.intersection(bounds)) possible_matches_index += c # Get unique candidates unique_candidate_matches = list(set(possible_matches_index)) possible_matches = gdf.iloc[unique_candidate_matches] # get final result if method == "within": ret_gdf = possible_matches.loc[possible_matches.within(areas.unary_union)] elif method == "intersects": ret_gdf = possible_matches.loc[possible_matches.intersects(areas.unary_union)] elif method == "crosses": ret_gdf = possible_matches.loc[possible_matches.crosses(areas.unary_union)] else: raise AttributeError( "method unknown. We only support ['within', 'intersects', 'crosses']. " f"You passed {method}" ) if re_project: return ret_gdf.to_crs(init_crs) else: return ret_gdf