[postgis-devel] ST_Area, ST_Area2D

[Mark Cave-Ayland]

Paul Ramsey wrote:
> Optional argument? :)
> 
> st_length(geom, [dim])
> 
> default is 2d regardless of input, [dim] = 3 allows you to get 3d if
> you need it.
> 
> P

Hmmm that seems like a lot of extra clutter. My feeling would be that 
the result returned should reflect the highest dimension input geometry, 
so as Regina suggests would be 2D length for a 2D line or 3D length for 
a 3D line. In terms of compliance, anyone inputting 3D geometries is 
already outside of the SFS 1.1 spec, and so I wouldn't feel bad about 
asking people to add a force_2d() call to switch the result if the 2D 
result is what they actually wanted. Common sense would suggest that if 
you have a 3D input, you'll get a 3D output.


ATB,

Mark.

-- 
Mark Cave-Ayland
Sirius Corporation - The Open Source Experts
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