[postgis-users] Finding the center of a street

[Luigi Castro Cardeles]

Hi Nelson,

i don't understand the problem with the T junctions but with the
non-contiguous sections you could create a contiguous linestring and use
that to find the middle point but you may get middle points that don't
intersects with then. Is this a problem?

[]'s
Luigi Castro Cardeles


2009/7/16 Nelson Correia <nelsonwc7 at hotmail.com>

>  Hi all,
>
> I have a database of streets, wich is composed by multilinestring segments.
> I want to find the centre of the street (i.e. the point that is in the
> middle and contained in the street geometry) and not the centroid (which may
> not be in the street).
>
> I can do this with linemerge (to obtain a linestring instead of a
> multilinestring) and then use the st_line_interpolate_point to calculate the
> middle point.
>
> The problem is with streets that have T junctions in the middle or that are
> composed by non-contiguous sections, for what I can't find a way to obtain a
> linestring to calculate the middle point.
>
> Anyone had a similar problem or know a solution to this problem?
>
> Thanks in advance!
>
> Nelson
>
>
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