在QGIS或PostGIS中将线层对齐到网络

我有公交路线上的GPS数据，现在我想将其捕捉到我的道路网络中。这两个层都是PostGIS DB中的线层。我想使用QGIS或PostGIS，但是如果必须使用GRASS或ArcMap，也可以。谢谢！

为了澄清，我试图将线对齐到线，而不是指向线。

我曾经拥有过这个功能。请注意，它会更改现有点表中的几何。我已经很长时间没有使用它了，但似乎应该可以完成工作。据我记得，如果您在两个表上都具有空间索引，它会很好地工作。为了称呼它

选择snap_point_to_line（'points_table'，'line_table'，500）。它将以500的公差捕捉，500是投影系统的单位。我曾经和Lambert合作。

    CREATE OR REPLACE FUNCTION snap_point_to_line(points_table character varying, line_table character varying, tolerance double precision)
      RETURNS boolean AS
    $BODY$
    DECLARE         
            srid integer;
            i integer;

            row record;
            row_1 record;
            closest_distance double precision;

            query varchar;
            snapped_point geometry;
    BEGIN

      --Get the srid of the points table
        FOR row IN EXECUTE 'select getsrid(the_geom) as srid from '||points_table||' where gid = (select min(gid) from '||points_table||')' LOOP
        END LOOP;
        srid := row.srid;


     -- Add a column in which it will store the closest nodes from the line
     FOR row IN EXECUTE 'SELECT the_geom FROM '||points_table LOOP

        query := 'SELECT ST_Transform(the_geom,'||srid||') as the_geom, ST_Distance(GeometryFromText('''||ST_AsText(row.the_geom)||''','||srid||'), ST_Transform(the_geom,'||srid||')) as distance FROM ' ||line_table||' ORDER BY ST_Distance(GeometryFromText('''||ST_AsText(row.the_geom)||''','||srid||'), ST_Transform(the_geom,'||srid||'))  LIMIT 1';
        RAISE NOTICE '%',query; 
        FOR row_1 IN EXECUTE query LOOP
            closest_distance := row_1.distance;

            --If below the distance threeshold, then snap the point
            IF closest_distance < tolerance THEN
                snapped_point := ST_line_interpolate_point(ST_LineMerge(row_1.the_geom),ST_line_locate_point(ST_LineMerge(row_1.the_geom), row.the_geom));

                --UPDATE the_geometry
                EXECUTE 'UPDATE '||points_table||' SET the_geom = GeometryFromText('''||ST_AsText(snapped_point)||''','||srid||') WHERE ST_AsText(the_geom) = '''||ST_AsText(row.the_geom)||'''';

            END IF;
END LOOP;   
    END LOOP;
    RETURN true;
    END;
   $BODY$
    LANGUAGE 'plpgsql' VOLATILE STRICT
    COST 100;
    ALTER FUNCTION snap_point_to_line(character varying, character varying, double precision) OWNER TO yourowner;