[postgis-tickets] [PostGIS] #2645: ST_LineInterpolatePoint incorrect output for vertical line

[PostGIS]

#2645: ST_LineInterpolatePoint incorrect output for vertical line
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 Reporter:  bencaradocdavies  |       Owner:  pramsey      
     Type:  enhancement       |      Status:  new          
 Priority:  high              |   Milestone:  PostGIS 2.1.2
Component:  postgis           |     Version:  2.1.x        
 Keywords:                    |  
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Changes (by pramsey):

  * type:  defect => enhancement


Comment:

 The interpolation is done in 2D and then the Z and M values of the
 generated point are created by interpolating between the values of the
 segment the point is located in. If we do the interpolation in full 3D,
 you could get a result like this...

 ST_LineInterpolatePoint('LINESTRING(0 0 0, 0 0.5 0, 0 1 100)', 0.5) ->
 'POINT(0 0.9 50)'

 Hard call. I'm not sure we want this to be a real 3d function, or a 2.5d
 function as it currently is. It's not a clear "bug" though.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/2645#comment:2>
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