STStartMeasure

STStartMeasure — Returns M value of first point in measured geometry.

Function Specification.

    Function STStartMeasure (
       @p_linestring geometry
    )
    Returns geometry 

Description.

Returns start measure associated with first point in a measured (multi)line-string.

If the line-string is not measured it returns 0.

Supports Linestrings with CircularString elements (2012).

Parameters.

    @p_linestring (geometry) - Supplied Linestring geometry.

Result.

This function returns the M ordinate value of first point in a measured line-string.

Example.

select [$(lrsowner)].[STStartMeasure](geometry::STGeomFromText('LINESTRING(1 1 2 3, 2 2 3 4)', 0)) as start_measure
union all
select [$(lrsowner)].[STStartMeasure](geometry::STGeomFromText('MULTILINESTRING((1 1 2 3, 2 2 3 4),(3 3 4 5,4 4 5 6))', 0))
union all
select [$(lrsowner)].[STStartMeasure](geometry::STGeomFromText('CIRCULARSTRING (3 6.325 NULL 0, 0 7 NULL 3.08, -3 6.325 NULL 6.15)',0))
GO

start_measure
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