[postgis-devel] st_dwithin, st_within, st_dcompletlywithin

Paul Ramsey pramsey at opengeo.org
Mon Jul 6 16:23:04 PDT 2009


It gets even more confusing if you note that some members of the WFS
working group insist that the semantics of the WithinDistance OGC
filter op are the semantics of your proposed function, rather than the
semantics of dwithin.

P

On Mon, Jul 6, 2009 at 4:19 PM, <nicklas.aven at jordogskog.no> wrote:
> Hallo
>
> This is a semantic question.
> I'm working with the new functions st_shortestline etc.
> I found that we can get another new function for free when we have
> implemented st_max_distance. By using the max-calculation instead of
> min-calculation the same way as st_dwithin, we insead get
> "st_dcompletlywithin" the function returns true if the maximum distance
> between the geometries is shorter than the third input.
>
> My question is (beside the question if this is something useble), what to
> call the function. I think it easily can be confusing. I mean, st_within and
> st_dwithin is two quite similar names wich is ok because they don't really
> relate to eachother in what they do, but if we add a function that do the
> same as st_dwithin but whith the difference that the geometries has to be
> completly inside the given distance of eachother, maybe we risk making it
> confusing. I guess st_dcompletlywithin is maybe the most describing, but
> very long.
>
> Greetings
> Nicklas
>
>
>
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