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<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=540135912-12112012>Honestly, I don't know where it comes from, but
st_buffer(geom, 0) often helps to "repair" polygon for some postgis
operations.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=540135912-12112012></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=540135912-12112012>Hugues.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=540135912-12112012></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=540135912-12112012>PS : I have some limitations to configure my
professional mail but my first name is Hugues and not François
;)</SPAN></FONT></DIV>
<DIV> </DIV>
<DIV align=left><FONT color=#0000ff size=2 face=Arial></FONT> </DIV><BR>
<DIV dir=ltr lang=fr class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>De :</B> postgis-users-bounces@lists.osgeo.org
[mailto:postgis-users-bounces@lists.osgeo.org] <B>De la part de</B> Angel
Cervera Claudio<BR><B>Envoyé :</B> lundi 12 novembre 2012
13:58<BR><B>À :</B> postgis-users@lists.osgeo.org<BR><B>Objet :</B>
Re: [postgis-users] st_difference throws an error<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV class=moz-cite-prefix>Hi Francois.<BR><BR>This work!<BR><BR>Could be a bug
in st_difference?<BR><BR>Thanks, Ángel<BR><BR>On 12/11/12 12:42, Francois Hugues
wrote:<BR></DIV>
<BLOCKQUOTE
cite=mid:3CB901080554B04881D30F111F62D9300229FD1D@nadia.grenoble.cemagref.fr
type="cite">
<META name=GENERATOR content="MSHTML 8.00.6001.19328">
<DIV dir=ltr align=left><SPAN class=554124111-12112012><FONT color=#0000ff
size=2 face=Arial>You should try the st_buffer tip :</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=554124111-12112012></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=554124111-12112012>select
st_astext(<BR>
st_difference(<BR>
st_buffer(st_geomfromtext('POLYGON((-5.66666 43.53301,-5.66704
43.53335,-5.66931 43.53374,-5.66975299919511 43.533380063154,-5.66979
43.53335,-5.66971 43.53478,-5.66969091189271
43.5348058613067,-5.67026768864541 43.5374211525033,-5.67084666354158
43.5376334432986,-5.67111 43.53773,-5.67059550578171 43.53754135212,-5.66854
43.53971,-5.66854 43.53971,-5.66854 43.53971,-5.66758 43.53976,-5.6665
43.5402,-5.6665 43.5402,-5.66609712188377 43.539781395014,-5.66401
43.54013,-5.66401 43.54013,-5.66351576708437 43.5392869195307,-5.66281
43.53909,-5.6626 43.53851,-5.66159162498075 43.5369268527413,-5.66131
43.53695,-5.66196 43.53617,-5.66272791899155
43.5356642562857,-5.66378432333548 43.5344801289574,-5.66384 43.53414,-5.66452
43.53344,-5.6656 43.53337,-5.66611 43.5331,-5.66666 43.53301))',
4326),0),<BR> st_buffer(st_geomfromtext('POLYGON((-5.66577
43.53447,-5.66612 43.53455,-5.66675167677363 43.5349178897119,-5.66735
43.53529,-5.66811 43.5355,-5.66786 43.53678,-5.66816 43.53697,-5.66801
43.53717,-5.66729498033211 43.5375449497042,-5.6665 43.53782,-5.66634200990626
43.5386936730934,-5.66634 43.53876,-5.66554366174751 43.5384386684555,-5.66521
43.53856,-5.66457 43.53781,-5.6640744056249 43.5375662650614,-5.66341231504476
43.5372589777288,-5.66324 43.53718,-5.66334987968078
43.536344363177,-5.66304550704754 43.5357063513112,-5.66299 43.53559,-5.66358
43.53544,-5.66413 43.53529,-5.66521 43.535,-5.66577 43.53447,-5.66577
43.53447))', 4326),0)<BR> )<BR>);</SPAN></DIV>
<DIV><SPAN class=554124111-12112012></SPAN> </DIV>
<DIV><SPAN class=554124111-12112012><FONT color=#0000ff size=2
face=Arial>Hugues.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><BR><BR></DIV><BR>
<DIV dir=ltr lang=fr class=OutlookMessageHeader align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>De :</B> <A class=moz-txt-link-abbreviated
href="mailto:postgis-users-bounces@lists.osgeo.org">postgis-users-bounces@lists.osgeo.org</A>
[<A class=moz-txt-link-freetext
href="mailto:postgis-users-bounces@lists.osgeo.org">mailto:postgis-users-bounces@lists.osgeo.org</A>]
<B>De la part de</B> Angel Cervera Claudio<BR><B>Envoyé :</B> lundi 12
novembre 2012 12:23<BR><B>À :</B> <A class=moz-txt-link-abbreviated
href="mailto:postgis-users@lists.osgeo.org">postgis-users@lists.osgeo.org</A><BR><B>Objet :</B>
[postgis-users] st_difference throws an
error<BR></FONT><BR></DIV><TT>Hello.<BR><BR>I post this problem in <A
class=moz-txt-link-freetext
href="http://gis.stackexchange.com/questions/40872/st-difference-throws-an-error"
moz-do-not-send="true">http://gis.stackexchange.com/questions/40872/st-difference-throws-an-error</A>
buy i'm sure in this mailing list people can help me.<BR><BR>I'm retrieving
"</TT><CODE>GEOSDifference: TopologyException: found non-noded intersection
between</CODE><TT>" error when executing st_difference sql.<BR><BR>Followed an
example:<BR><BR>Error: </TT><BR><PRE><CODE>ERROR: GEOSDifference: TopologyException: found non-noded intersection between LINESTRING (-5.67027 43.5374, -5.67085 43.5376) and LINESTRING (-5.67111 43.5377, -5.6706 43.5375) at -5.6708422794605911 43.537631835802237
SQL:
</CODE><CODE>select st_astext(
st_difference(
st_geomfromtext('POLYGON((-5.66666 43.53301,-5.66704 43.53335,-5.66931 43.53374,-5.66975299919511 43.533380063154,-5.66979 43.53335,-5.66971 43.53478,-5.66969091189271 43.5348058613067,-5.67026768864541 43.5374211525033,-5.67084666354158 43.5376334432986,-5.67111 43.53773,-5.67059550578171 43.53754135212,-5.66854 43.53971,-5.66854 43.53971,-5.66854 43.53971,-5.66758 43.53976,-5.6665 43.5402,-5.6665 43.5402,-5.66609712188377 43.539781395014,-5.66401 43.54013,-5.66401 43.54013,-5.66351576708437 43.5392869195307,-5.66281 43.53909,-5.6626 43.53851,-5.66159162498075 43.5369268527413,-5.66131 43.53695,-5.66196 43.53617,-5.66272791899155 43.5356642562857,-5.66378432333548 43.5344801289574,-5.66384 43.53414,-5.66452 43.53344,-5.6656 43.53337,-5.66611 43.5331,-5.66666 43.53301))', 4326),
st_geomfromtext('POLYGON((-5.66577 43.53447,-5.66612 43.53455,-5.66675167677363 43.5349178897119,-5.66735 43.53529,-5.66811 43.5355,-5.66786 43.53678,-5.66816 43.53697,-5.66801 43.53717,-5.66729498033211 43.5375449497042,-5.6665 43.53782,-5.66634200990626 43.5386936730934,-5.66634 43.53876,-5.66554366174751 43.5384386684555,-5.66521 43.53856,-5.66457 43.53781,-5.6640744056249 43.5375662650614,-5.66341231504476 43.5372589777288,-5.66324 43.53718,-5.66334987968078 43.536344363177,-5.66304550704754 43.5357063513112,-5.66299 43.53559,-5.66358 43.53544,-5.66413 43.53529,-5.66521 43.535,-5.66577 43.53447,-5.66577 43.53447))', 4326)
)
);</CODE>
In <TT>gis.stackexchange.com i attached images with various shapes with this problem.
</TT>All share a common pattern. Some parts of edge are near to be parallel.
How to resolve this problem? Is a bug?
Thanks!
</PRE></BLOCKQUOTE></BODY></HTML>