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<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>Mehmet,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>One point does not make a linestring :)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>I suppose what you could do is change these to points with
something of the form</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>UPDATE ways</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>SET linestring = ST_PointN(linestring,1)</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>WHERE ST_NPoints(linestring) = 1</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>though you'll need to drop your geometry type constraint on
your table first to do that.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>Alternatively you could just delete these records sine
they are cases where ST_MakeLine had only one point in the
result).</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>Hope that helps,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=920491419-27102009><FONT color=#0000ff
size=2 face=Arial>Regina</FONT></SPAN></DIV><BR>
<DIV dir=ltr lang=en-us class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of
</B>Mehmet Sirin<BR><B>Sent:</B> Tuesday, October 27, 2009 3:13 PM<BR><B>To:</B>
PostGIS Users Discussion<BR><B>Subject:</B> Re: [postgis-users] ST_UNION -
Exception in LWGEOM2GEOS<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV>Hi, <BR></DIV>
<DIV>indeed there are some linestrings with only 1 Point.</DIV>
<DIV>But I don't know how come.. after checking these points I saw that they are
nothing but normal </DIV>
<DIV>points on the way ,that means nothing special that should cause a
problem.</DIV>
<DIV></DIV>
<DIV>one of then is on the way 'Ahlde' -> "LINESTRING(7.3402594
52.3361277)"</DIV>
<DIV></DIV>
<DIV>maybe you should know, that I imported data via osmosis and then created
linestringsby using :</DIV>
<DIV></DIV>
<DIV> UPDATE ways w SET linestring = (<BR> SELECT MakeLine(c.geom)
AS way_line FROM (<BR> SELECT n.geom AS geom FROM nodes n INNER JOIN
way_nodes <BR>wn ON <A href="http://n.id">n.id</A> = wn.node_id<BR>
WHERE (wn.way_id = <A href="http://w.id">w.id</A>) ORDER BY
wn.sequence_id<BR> ) c<BR> );<BR><BR></DIV>
<DIV></DIV><BR>
<DIV class=gmail_quote>2009/10/27 Paragon Corporation <SPAN dir=ltr><<A
href="mailto:lr@pcorp.us">lr@pcorp.us</A>></SPAN><BR>
<BLOCKQUOTE
style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex"
class=gmail_quote>
<DIV>
<DIV dir=ltr align=left><SPAN><FONT color=#0000ff size=2
face=Arial>Mehmet,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN><FONT color=#0000ff size=2 face=Arial>It sounds
like your line string might have 0 or 1 points.</FONT></SPAN></DIV>
<DIV dir=ltr align=left> </DIV>
<DIV dir=ltr align=left><SPAN><FONT color=#0000ff size=2
face=Arial>Use</FONT></SPAN></DIV>
<DIV dir=ltr align=left> </DIV>
<DIV dir=ltr align=left><SPAN><FONT color=#0000ff size=2
face=Arial>ST_NPoints(linestring) < 2 to find all linestrings with
fewer than 2 points</FONT></SPAN></DIV>
<DIV dir=ltr align=left> </DIV>
<DIV dir=ltr align=left><SPAN><FONT color=#0000ff size=2
face=Arial>Leo</FONT></SPAN></DIV><BR>
<DIV dir=ltr lang=en-us align=left>
<HR>
<FONT size=2 face=Tahoma><B>From:</B> <A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A> [mailto:<A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A>] <B>On Behalf
Of </B>Mehmet Sirin<BR><B>Sent:</B> Monday, October 26, 2009 7:24
PM<BR><B>To:</B> PostGIS Users Discussion<BR><B>Subject:</B> [postgis-users]
ST_UNION - Exception in LWGEOM2GEOS<BR></FONT><BR></DIV>
<DIV>
<DIV class=h5>
<DIV>Hi,<BR></DIV>
<DIV>I just tried to create a mutlilinestring out of a set of linestrings
via </DIV>
<DIV>SELECT AsText( ST_UNION(linestring) )<BR><BR>FROM ways w, way_tags wt
WHERE <A href="http://w.id" target=_blank>w.id</A>=wt.way_id <BR>AND
wt.v='Dörnter Weg'<BR><BR></DIV>
<DIV>(it lies in Osnabrück, lower saxony)</DIV>
<DIV>but I'm getting this strange error: </DIV>
<DIV>HINWEIS: IllegalArgumentException: point array must contain 0 or >1
elements<BR><BR><BR>FEHLER: Exception in LWGEOM2GEOS<BR><BR>********** Fehler
**********<BR><BR>FEHLER: Exception in LWGEOM2GEOS<BR>SQL
Status:XX000<BR><BR><BR></DIV>
<DIV>Replacing wt.v='Dörnter Weg' with wt.v='Some other Streets' it
works properly. </DIV>
<DIV>So it is because of this street 'Dörnter Weg' (i got a few other ones of
this kind in my database). </DIV>
<DIV>Anybody can tell me why these sort of ways leads to a problem?</DIV>
<DIV>thank you</DIV>
<DIV>kind regards</DIV>
<DIV>mehmet
sirin</DIV></DIV></DIV></DIV><BR>_______________________________________________<BR>postgis-users
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