Finding the centroid of a polyline

Question

Hi.
I am trying to write a function that will return the centroid of an input polyline. I have come up with two possible solutions, but both are problematic in different ways...
This first function returns an error:
ORA-00600: internal error code
Our DBA is looking in to this, but so far with no success
The second function seems to work ok, but is very slow. It takes over half an hour to process the first 10,000 records in my table (there are 270,000 in all)
Any suggestions as to what the problem might be with the first function, or how to speed up the second?
Thanks!
1
create or replace function get_line_centroid(geoloc MDSYS.SDO_GEOMETRY) return MDSYS.SDO_GEOMETRY
as
mbr MDSYS.SDO_GEOMETRY;
centroid MDSYS.SDO_GEOMETRY;
begin
mbr := MDSYS.SDO_GEOM.SDO_MBR(geoloc);
If SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT(mbr, 0.05) = 'TRUE' Then
centroid := MDSYS.SDO_GEOM.SDO_CENTROID(mbr, 0.05);
End If;
return centroid;
end;
2
create or replace function get_line_centroid(geoloc MDSYS.SDO_GEOMETRY) return MDSYS.SDO_GEOMETRY
as
lrs_seg MDSYS.SDO_GEOMETRY;
centroid MDSYS.SDO_GEOMETRY;
begin
lrs_seg := SDO_LRS.CONVERT_TO_LRS_GEOM(geoloc);
centroid := SDO_LRS.LOCATE_PT(lrs_seg, SDO_LRS.PERCENTAGE_TO_MEASURE(lrs_seg, 50));
return SDO_LRS.CONVERT_TO_STD_GEOM(centroid);
end;

Answer 1

Hi All.
Well I have still not figured why my first function was failing, but I have discovered a much faster alternative to the second one...
This is to perform a manual computation of the centroid using the coordinates in the ordinate array of the line.
Quite straight forward :)