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List:       postgis-users
Subject:    [postgis-users] Intersection between segments in multilinestring
From:       Mehmet Sirin <m.sirin07 () googlemail ! com>
Date:       2009-10-31 10:45:43
Message-ID: 55744b1c0910310345r372d6e42qb70fc6c49defdfc9 () mail ! gmail ! com
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Hi,

I'm trying to dicern equally named ways in different areas. For that I have
to know which segments in the multilinestring or collection are connected t=
o
each other and which not.
Of course I could create a function that checks all parts that have the sam=
e
name if there is a touch to each other etc..
But before doing so, i want to ask you if there might be an easier way to
return all touching elements ( that later form a street that I can differ
from the other..)?

Maybe you don't understand my intention, so again:



----------=B0-----=B0----
..=B0
..|
..|=B0------
..|



this is street "villageway" with 5 segments (4touches shown with " =B0 ") .=
 A
few miles away there is another street:



----=B0-------------



this street is named "villageway", too. It has only 2 segments.




To differentiate between those ways, I have to figure out which parts of
way1 are connected to each other..And if there is no intersection, touch or
whatever with one of the segments existing in way1 anymore, but still there
are some parts that are named "villageway", I know that thesere parts belon=
g
to the other street.

But perhaps i could make it easier by creating a bounding box surrounding
both ways an then take a horizontal or a vertical line and test if there is
both a way in the upper part of the bbox and one in the lower part. that
means 2 different ways.. hmm seems to be silly :D



kind regards
mehmet

[Attachment #5 (text/html)]

Hi,<div><br><div>I&#39;m trying to dicern equally named ways in different a=
reas. For that I have to know which segments in the multilinestring or coll=
ection are connected to each other and which not.=A0</div><div>Of course I =
could create a function that checks all parts that have the same name if th=
ere is a touch to each other etc..</div>
<div>But before doing so, i want to ask you if there might be an easier way=
 to return all touching elements ( that later form a street that I can diff=
er from the other..)?</div><div><br></div><div>Maybe you don&#39;t understa=
nd my intention, so again:</div>
<div><br></div><div><br></div><div><br></div><div>----------=B0-----=B0----=
</div><div>..=B0</div><div>..|</div><div>..|=B0------</div><div>..|</div><d=
iv><br></div><div><br></div><div><br></div><div>this is street &quot;villag=
eway&quot; with 5 segments (4touches shown with &quot; =B0 &quot;) . A few =
miles away there is another street:</div>
<div><br></div><div><br></div><div><br></div><div>----=B0-------------</div=
><div><br></div><div><br></div><div><br></div><div>this street is named &qu=
ot;villageway&quot;, too. It has only 2 segments.</div><div><br></div><div>
<br></div><div><br></div><div><br></div><div>To differentiate between those=
 ways, I have to figure out which parts of way1 are connected to each other=
..And if there is no intersection, touch or whatever with one of the segmen=
ts existing in way1 anymore, but still there are some parts that are named =
&quot;villageway&quot;, I know that thesere parts belong to the other stree=
t.</div>
<div><br></div><div>But perhaps i could make it easier by creating a boundi=
ng box surrounding both ways an then take a horizontal or a vertical line a=
nd test if there is both a way in the upper part of the bbox and one in the=
 lower part. that means 2 different ways.. hmm seems to be silly :D</div>
<div><br></div><div><br></div><div><br></div><div>kind regards=A0</div><div=
>mehmet</div></div>


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