The requirement to extend a linestring is quite common in the world of a practitioner. This can be done by coding a single ST_Extend member function. The rules that will govern this function are:
Operates only on linestrings
Allows for shortening via provision of a negative extension distance
Can be applied to the start, end, or both ends at the same time
Negative extension distances that could collapse the linestring to nothing need to be captured
The function's declaration in the T_Geometry type is as follows:
Create Or Replace TYPE T_Geometry As Object (
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Member Function
ST_Extend(p_extend_dist In number,
p_start_end In varchar2 default 'START',
p_unit In varchar2 default null)
Return T_Geometry Deterministic,The ST_Extend function's p_extend_dist parameter can be applied in two ways. Firstly, if the supplied value is negative, the underlying linestring is shortened; if positive, the linestring is extended.
The p_start_end...