[postgis-users] Union fails on 2389 linestrings.

Tue Aug 3 11:32:50 PDT 2010

This example works fine in the current JTS codebase.  It's a bit 
surprising this fails in PostGIS, since the topology requirements for 
LineStrings are very low (as compared to polygonal data).  There may be 
an issue in GEOS which is causing this.

In the meantime you can always use JTS over PostGIS via JEQL....  8^)

Jeff Adams wrote:
> OK, I finally have it down to a manageable use case.  Union these 16
> linestrings, you get a topology exception.  Remove any one of them, you
> don't.  What the heck can I do about this?  Simplifying and snapping to
> grid, at any reasonable precision, did not help my larger real data (I
> didn't try with this little test case).
>
> Is there any chance that ST_Union has a bug?  Isn't it supposed to be adding
> the node it complains is missing?
>
> SELECT ST_Union(ARRAY[
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.30613361296
> 33.8122380826708,-118.304098 33.810251,-118.304236 33.810103,-118.304709
> 33.810071,-118.305765 33.810748,-118.305909 33.809732,-118.306626
> 33.809556,-118.306593 33.808887,-118.307343 33.808265,-118.307262
> 33.808031,-118.306361 33.807514,-118.304929 33.807514,-118.304845
> 33.807291,-118.305287 33.806817,-118.306369 33.806816,-118.306362
> 33.804825,-118.307257 33.80412,-118.307256 33.803689,-118.306994
> 33.803306,-118.307001 33.802282,-118.306366 33.801427,-118.304812
> 33.801424,-118.304852 33.800714,-118.304474 33.799426,-118.304048
> 33.799149,-118.303735 33.798054,-118.302859 33.798053,-118.302692
> 33.797818,-118.3043 33.796488,-118.304414 33.796697,-118.305316
> 33.796699,-118.305309 33.795842,-118.305185 33.795766,-118.307667
> 33.793712,-118.307871 33.79377,-118.307762 33.794063,-118.308329
> 33.794165,-118.309331 33.794785,-118.309496 33.794646,-118.309026
> 33.793433,-118.309301 33.793431,-118.310179 33.792369,-118.311477
> 33.792408,-118.311221 33.791529,-118.312053 33.789477,-118.314394
> 33.78809,-118.314441 33.787542,-118.314939 33.787103,-118.314933
> 33.787655,-118.316174 33.788043,-118.317662 33.786051,-118.317822
> 33.785331,-118.31926 33.783198,-118.319515 33.783401,-118.31952
> 33.784353,-118.320133 33.784875,-118.320168 33.785781,-118.320644
> 33.786331,-118.321187 33.786329,-118.321664 33.785748,-118.322465
> 33.786108,-118.322465 33.785588,-118.322725 33.785508,-118.322861
> 33.785552,-118.322863 33.787017,-118.324012 33.786812,-118.324484
> 33.78618,-118.324536 33.785867,-118.325534 33.786479,-118.327373
> 33.786445,-118.32739 33.78696,-118.328084 33.7867,-118.328192
> 33.786312,-118.329673 33.786315,-118.330558 33.786692,-118.331564
> 33.78613,-118.332317 33.786324,-118.333303 33.785763,-118.333296
> 33.7829,-118.334243 33.781681,-118.334739 33.781502,-118.336465
> 33.782973,-118.337471 33.78022,-118.338271 33.779854,-118.33873
> 33.779245,-118.339713 33.7811,-118.340119 33.779571,-118.340489
> 33.779635,-118.340011 33.778281,-118.34055 33.777196,-118.34009
> 33.777247,-118.339995 33.77709,-118.341573 33.776763,-118.342003
> 33.776325,-118.342988 33.777413,-118.343422 33.776597,-118.342638
> 33.77558,-118.343555 33.776151,-118.343818 33.776151,-118.344472
> 33.775277,-118.344577 33.775582,-118.343992 33.776306,-118.344084
> 33.77655,-118.344886 33.77729,-118.348172 33.779425,-118.349097388008
> 33.7794492053201)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.307700993013
> 33.8134536081132,-118.307366 33.813558,-118.306908 33.812743,-118.304434
> 33.810553,-118.304622 33.810418,-118.30525 33.810988,-118.305923
> 33.810719,-118.306 33.810101,-118.306704 33.809973,-118.306688
> 33.809247,-118.307466 33.808468,-118.307319 33.808037,-118.306547
> 33.807529,-118.30539 33.807538,-118.305338 33.807293,-118.305635
> 33.806943,-118.30707 33.806906,-118.307423 33.806221,-118.307375
> 33.805322,-118.307014 33.80495,-118.307489 33.8043,-118.30749
> 33.803281,-118.307227 33.803082,-118.30738 33.802612,-118.307223
> 33.802298,-118.307267 33.801238,-118.306917 33.801077,-118.305484
> 33.801074,-118.305272 33.800949,-118.305345 33.800715,-118.304968
> 33.799428,-118.305239 33.7988,-118.304129 33.7988,-118.303185
> 33.797819,-118.304138 33.797653,-118.304135 33.797435,-118.303851
> 33.797269,-118.306955 33.794712,-118.307505 33.794711,-118.30766
> 33.794122,-118.30946 33.793419,-118.310673 33.792496,-118.311722
> 33.792499,-118.31194 33.792328,-118.311811 33.791541,-118.312067
> 33.79133,-118.312203 33.791282,-118.312207 33.792323,-118.312605
> 33.793072,-118.313723 33.79307,-118.314322 33.792613,-118.314338
> 33.791002,-118.313872 33.790674,-118.314438 33.790629,-118.314586
> 33.790086,-118.31479 33.790069,-118.314784 33.790818,-118.315957
> 33.790293,-118.316272 33.79029,-118.316276 33.789496,-118.317512
> 33.788665,-118.317508 33.78897,-118.317922 33.789289,-118.319415
> 33.789292,-118.319822 33.788966,-118.319822 33.787578,-118.320026
> 33.787281,-118.320228 33.787282,-118.320228 33.788607,-118.321767
> 33.787298,-118.321769 33.78668,-118.322724 33.785959,-118.32286
> 33.786049,-118.322864 33.787241,-118.324012 33.786846,-118.324477
> 33.786221,-118.324536 33.785867,-118.325534 33.786479,-118.327373
> 33.786445,-118.32739 33.78696,-118.328084 33.7867,-118.328192
> 33.786312,-118.329976 33.786391,-118.330383 33.786205,-118.330798
> 33.786434,-118.331589 33.786157,-118.333241 33.786522,-118.33319
> 33.785878,-118.333446 33.785733,-118.333249 33.78524,-118.333293
> 33.783478,-118.333551 33.783132,-118.33375 33.783734,-118.337252
> 33.784222,-118.337272 33.78409,-118.337582 33.78435,-118.337953
> 33.784311,-118.338888 33.785102,-118.339435 33.784442,-118.339977
> 33.784578,-118.340642 33.783119,-118.341129 33.782651,-118.341162
> 33.782983,-118.340942 33.783344,-118.34147 33.784,-118.342781
> 33.785206,-118.343369 33.785377,-118.343965 33.78596,-118.344404
> 33.785906,-118.345565 33.785188,-118.346632 33.784948,-118.346263
> 33.785593,-118.345294 33.786038,-118.343339 33.787391,-118.342914
> 33.788404,-118.344329 33.789551,-118.344834 33.789647,-118.345547
> 33.790826,-118.346802 33.791674,-118.346973 33.792355,-118.347339
> 33.79248,-118.348118 33.793207,-118.348143 33.793939,-118.348962
> 33.793846,-118.349103 33.793586,-118.349468 33.793472,-118.350038
> 33.792956,-118.350515 33.792864,-118.351036 33.792069,-118.353376
> 33.790784,-118.355734 33.789024,-118.355245 33.788011,-118.356367
> 33.786715,-118.354972 33.78611,-118.354149 33.786328,-118.354231
> 33.784792,-118.354544 33.784053,-118.355962 33.784602,-118.357489
> 33.785796,-118.358813435042 33.7855261326062)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.304848630339
> 33.8111422006911,-118.304605 33.810709,-118.303261 33.809465,-118.303066
> 33.808994,-118.303047 33.808764,-118.304678 33.808727,-118.304204
> 33.807417,-118.303217 33.807414,-118.303039 33.807564,-118.30284
> 33.807286,-118.303155 33.80711,-118.305469 33.807118,-118.305132
> 33.805605,-118.304916 33.805121,-118.304567 33.80512,-118.304624
> 33.804945,-118.303265 33.801157,-118.302756 33.801007,-118.300683
> 33.797815,-118.301197 33.797388,-118.301319 33.797708,-118.302268
> 33.79771,-118.302535 33.797461,-118.302534 33.7971,-118.301946
> 33.796762,-118.302558 33.796716,-118.302656 33.796386,-118.302522
> 33.796285,-118.303826 33.795209,-118.304173 33.795212,-118.304241
> 33.794877,-118.305718 33.793661,-118.307238 33.793667,-118.307507
> 33.793434,-118.30751 33.792915,-118.307226 33.792558,-118.307047
> 33.792557,-118.307673 33.792037,-118.307796 33.792023,-118.307974
> 33.792387,-118.30957 33.792391,-118.309312 33.791501,-118.3106
> 33.790482,-118.310854 33.790483,-118.311109 33.790064,-118.312064
> 33.789273,-118.314397 33.78883,-118.314404 33.78825,-118.314596
> 33.78801,-118.314802 33.788004,-118.314793 33.788736,-118.316043
> 33.788337,-118.316826 33.788339,-118.317112 33.787982,-118.317143
> 33.786759,-118.317543 33.786583,-118.317784 33.787485,-118.318591
> 33.787418,-118.319824 33.787894,-118.319819 33.785511,-118.320017
> 33.785203,-118.320221 33.78533,-118.320225 33.786017,-118.320425
> 33.786482,-118.321244 33.78648,-118.321721 33.785898,-118.322521
> 33.78602,-118.322522 33.785558,-118.322861 33.785552,-118.322863
> 33.787017,-118.324012 33.786812,-118.324484 33.78618,-118.324536
> 33.785867,-118.325473 33.786414,-118.327192 33.786568,-118.327159
> 33.786393,-118.32913 33.786126,-118.330072 33.786179,-118.330661
> 33.78648,-118.331149 33.786488,-118.33146 33.786208,-118.33199
> 33.786395,-118.333088 33.786362,-118.333197 33.784267,-118.333617
> 33.783891,-118.333541 33.782489,-118.334243 33.781681,-118.334727
> 33.781597,-118.337372 33.783843,-118.337801 33.782229,-118.337775
> 33.78179,-118.337228 33.781161,-118.338482 33.780641,-118.338787
> 33.78142,-118.339889 33.781405,-118.340305 33.78154,-118.340372
> 33.779912,-118.340702 33.779767,-118.342003 33.779991,-118.342707
> 33.778679,-118.343946 33.780445,-118.343594 33.781199,-118.34191
> 33.782263,-118.341886 33.783636,-118.343458 33.784865,-118.344662
> 33.785274,-118.345142 33.784764,-118.346172 33.784403,-118.347436
> 33.784214,-118.347888 33.784652,-118.348115 33.7844,-118.348775
> 33.784432,-118.350288 33.784162,-118.351655 33.782986,-118.351467
> 33.782198,-118.350625 33.781652,-118.350715 33.781321,-118.350949
> 33.781314,-118.352025 33.78202,-118.352465 33.782066,-118.352774
> 33.780824,-118.352971 33.780656,-118.355227 33.782384,-118.355679
> 33.78227,-118.355689 33.781705,-118.356677 33.781749,-118.357000162508
> 33.7819097651871)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.357169759789
> 33.7834490284716,-118.357033 33.783851,-118.357898
> 33.784215,-118.359328629247 33.784207709798)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.303089803431
> 33.8096422063087,-118.30301 33.808914,-118.302281
> 33.808821,-118.302230554228 33.8087352371279)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.301521804907
> 33.8075302921941,-118.301284 33.807126,-118.299501 33.805505,-118.29965
> 33.805337,-118.300478 33.806088,-118.300959 33.805355,-118.301754
> 33.80542,-118.302461 33.8049,-118.300752 33.803522,-118.300736
> 33.802591,-118.29908 33.800009,-118.299078 33.79936,-118.298126
> 33.798199,-118.297897 33.798196,-118.297542 33.798694,-118.296491
> 33.797739,-118.297443 33.797578,-118.297399 33.796956,-118.297636
> 33.796822,-118.29767 33.797187,-118.297998 33.797514,-118.299227
> 33.797578,-118.29968 33.797272,-118.299688 33.796031,-118.299392
> 33.795709,-118.299874 33.795499,-118.299915 33.794929,-118.30138
> 33.793734,-118.302011 33.793739,-118.302555 33.793521,-118.301943
> 33.79327,-118.302688 33.79317,-118.302722 33.792626,-118.302976
> 33.792415,-118.303621 33.792417,-118.303482 33.791996,-118.304351
> 33.791287,-118.305664 33.791398,-118.305345 33.790471,-118.306815
> 33.790407,-118.307346 33.790006,-118.306795 33.789544,-118.306567
> 33.789543,-118.306835 33.789398,-118.307507 33.789402,-118.307649
> 33.789276,-118.307718 33.788531,-118.307919 33.788787,-118.309149
> 33.788796,-118.309397 33.788545,-118.30911 33.788213,-118.309956
> 33.787547,-118.31168 33.787433,-118.311612 33.786862,-118.312713
> 33.785993,-118.312834 33.785971,-118.31279 33.786371,-118.313089
> 33.786427,-118.313412 33.786157,-118.314404 33.786276,-118.314426
> 33.785601,-118.313755 33.785209,-118.314624 33.785098,-118.314696
> 33.784527,-118.315529 33.784589,-118.315858 33.785109,-118.316121
> 33.786327,-118.316484 33.786947,-118.317697 33.785776,-118.317923
> 33.784866,-118.318853 33.784151,-118.318883 33.783487,-118.319275
> 33.783116,-118.319695 33.78206,-118.319977 33.782698,-118.319707
> 33.78376,-118.319754 33.784296,-118.320396 33.784866,-118.32043
> 33.785632,-118.321971 33.785845,-118.322728 33.785326,-118.324198
> 33.786022,-118.324267 33.785631,-118.325005 33.786193,-118.325794
> 33.786532,-118.326632 33.786509,-118.326488 33.786846,-118.32664
> 33.786845,-118.326819 33.787409,-118.326993 33.787409,-118.327278
> 33.786916,-118.327253 33.786443,-118.328893 33.786306,-118.32939
> 33.786114,-118.330125 33.786169,-118.330733 33.78648,-118.331513
> 33.786198,-118.333173 33.78661,-118.333114 33.785919,-118.333302
> 33.785783,-118.333173 33.785281,-118.333247 33.784311,-118.333624
> 33.783764,-118.333511 33.782611,-118.334297 33.781646,-118.336277
> 33.783248,-118.336621 33.78325,-118.338452 33.784795,-118.33917
> 33.784288,-118.339476 33.783346,-118.339385 33.782988,-118.339631
> 33.782794,-118.338909 33.781621,-118.340143 33.781607,-118.340929
> 33.780816,-118.341792 33.780975,-118.342079 33.780189,-118.34225
> 33.780101,-118.342615 33.780504,-118.342196 33.781688,-118.341381
> 33.783009,-118.341979 33.783894,-118.343081 33.784838,-118.344449
> 33.785454,-118.345181 33.784944,-118.346233 33.784494,-118.346648
> 33.784836,-118.349171 33.784624,-118.349984 33.784341,-118.353068
> 33.785771,-118.353056 33.783686,-118.352762 33.783051,-118.352003
> 33.782798,-118.352097 33.782229,-118.352621 33.782097,-118.352685
> 33.782538,-118.353197 33.782903,-118.353692 33.782857,-118.353489
> 33.782097,-118.353978 33.782284,-118.354301 33.782759,-118.354704
> 33.782671,-118.354936 33.782421,-118.355333 33.782578,-118.355198
> 33.782707,-118.355458 33.783551,-118.35688 33.783258,-118.35714707651
> 33.7835707923095)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.357401619265
> 33.7838689054455,-118.357879 33.784428,-118.357962
> 33.785686,-118.358889500305 33.7854213315776)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.308746858587
> 33.8175427468454,-118.308708 33.817061,-118.30847770782 33.8169411415257)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.307561901608
> 33.8160004041704,-118.307515 33.814991,-118.307658
> 33.814793,-118.307628474836 33.8146729847436)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.307382137965
> 33.8136716631955,-118.307365 33.813602,-118.307043979511 33.813016336587)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.307042066317
> 33.8130128461942,-118.306881 33.812719,-118.303923 33.810094,-118.304036
> 33.80994,-118.304256 33.810138,-118.304885 33.810011,-118.305908
> 33.810079,-118.305874 33.80954,-118.306606 33.809107,-118.306362
> 33.808818,-118.307278 33.808159,-118.30716 33.807777,-118.306317
> 33.807502,-118.304689 33.807501,-118.304588 33.807291,-118.305031
> 33.806816,-118.306114 33.806818,-118.306106 33.804825,-118.307088
> 33.804119,-118.306973 33.80209,-118.30611 33.801426,-118.304556
> 33.801423,-118.303994 33.799329,-118.304026 33.798643,-118.303713
> 33.798054,-118.302711 33.798053,-118.302435 33.797818,-118.305056
> 33.79566,-118.306831 33.795665,-118.306617 33.795237,-118.30609
> 33.794802,-118.307666 33.793498,-118.309843 33.792447,-118.310571
> 33.792504,-118.310883 33.791627,-118.312094 33.790712,-118.314204
> 33.790586,-118.314398 33.790274,-118.314358 33.789593,-118.314589
> 33.789463,-118.314711 33.789504,-118.314661 33.790251,-118.315831
> 33.790306,-118.315512 33.789507,-118.316943 33.78944,-118.31714
> 33.789014,-118.316546 33.788727,-118.317516 33.78804,-118.31751
> 33.788755,-118.318006 33.789196,-118.319333 33.789198,-118.319822
> 33.788747,-118.319822 33.786954,-118.320026 33.786657,-118.320254
> 33.786592,-118.320228 33.78807,-118.321768 33.786763,-118.321722
> 33.786007,-118.322725 33.785508,-118.322861 33.785552,-118.322863
> 33.787017,-118.324012 33.786812,-118.324484 33.78618,-118.324536
> 33.785867,-118.325534 33.786479,-118.327373 33.786445,-118.32739
> 33.78696,-118.328084 33.7867,-118.328192 33.786312,-118.329673
> 33.786315,-118.330522 33.786672,-118.331562 33.786128,-118.332314
> 33.786323,-118.33323 33.785922,-118.333379 33.784045,-118.333293
> 33.782898,-118.334243 33.781681,-118.334734 33.78154,-118.336434
> 33.782989,-118.337364 33.780521,-118.338572 33.779886,-118.340304
> 33.779689,-118.341613 33.779914,-118.342106 33.779586,-118.342518
> 33.77815,-118.342987 33.777958,-118.344659 33.7805,-118.343381
> 33.780906,-118.343632 33.781143,-118.342398 33.783934,-118.343512
> 33.784819,-118.344915 33.784888,-118.34587 33.784421,-118.347695
> 33.784125,-118.348113 33.78462,-118.350786 33.78368,-118.351221
> 33.783293,-118.349414 33.781941,-118.349272 33.780323,-118.351328
> 33.780357,-118.352627 33.78109,-118.353084 33.77979,-118.353488
> 33.779397,-118.353845 33.77931,-118.354605 33.779992,-118.354302
> 33.780391,-118.354036 33.781226,-118.355018 33.780952,-118.355374
> 33.781143,-118.3558 33.780502,-118.356525457447 33.7806494603301)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.357238541314
> 33.7806010373294,-118.357325612665 33.7805398901349)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.357342573846
> 33.7805383054012,-118.357615033695 33.7806751225237)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.357693277501
> 33.7809493965079,-118.357455525965 33.7813634913787)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.357444440338
> 33.7838848876304,-118.357453 33.783942,-118.357982
> 33.784141,-118.35917094071 33.7841021918463)'),
> ST_GeomFromEWKT('SRID=4326;LINESTRING(-118.29510929418
> 33.7752042976004,-118.295895 33.775667,-118.295975 33.775514,-118.296254
> 33.775883,-118.296184 33.778951,-118.296341 33.77951,-118.297119
> 33.780547,-118.298343 33.780232,-118.299024 33.779858,-118.299207
> 33.778491,-118.299472 33.778718,-118.301295 33.779122,-118.301733
> 33.778885,-118.30297 33.778888,-118.303043 33.779769,-118.303358
> 33.779732,-118.303983 33.778992,-118.303682 33.77972,-118.304919
> 33.779888,-118.304667 33.780495,-118.303892 33.780511,-118.30404
> 33.781208,-118.303359 33.781416,-118.304219 33.782044,-118.304214
> 33.782771,-118.305056 33.782756,-118.3054 33.783381,-118.305683
> 33.783381,-118.30588 33.783663,-118.305981 33.7843,-118.307116
> 33.785157,-118.307545 33.785104,-118.309046 33.78565,-118.309874
> 33.786831,-118.3097 33.787235,-118.309963 33.787412,-118.310398
> 33.787411,-118.311112 33.78786,-118.311488 33.787548,-118.31177
> 33.787632,-118.311792 33.787809,-118.311122 33.788364,-118.312091
> 33.788904,-118.312363 33.789343,-118.31268 33.789485,-118.310864
> 33.791643,-118.309697 33.791608,-118.309507 33.792027,-118.309862
> 33.792454,-118.308861 33.79445,-118.3088 33.794935,-118.30625
> 33.796639,-118.30641 33.796778,-118.305036 33.796853,-118.304479
> 33.7973,-118.305042 33.797743,-118.305281 33.797743,-118.304355
> 33.798502,-118.303949 33.79877,-118.303609 33.798097,-118.300308
> 33.798092,-118.301358 33.800068,-118.301353 33.800585,-118.301167
> 33.801237,-118.30032 33.802052,-118.29926 33.80198,-118.299237
> 33.802909,-118.298648 33.804168,-118.297427 33.804616,-118.29581032417
> 33.804010103814)')
> ]) as broken;
>
> NOTICE:  TopologyException: found non-noded intersection between LINESTRING
> (-118.323 33.7869, -118.323 33.7869) and LINESTRING (-118.323 33.7869,
> -118.323 33.7869) at -118.323 33.7869
>
>
> ERROR:  GEOS union() threw an error!
>
> ********** Error **********
>
> ERROR: GEOS union() threw an error!
> SQL state: XX000
>
>
>
> On Wed, Jul 28, 2010 at 9:18 AM, Jeff Adams <jadams at azavea.com> wrote:
>
>   
>> The ST_SnapToGrid doesn't help.  It changes the points slightly, but Union
>> still fails.  I tried simplifying my input linework, snapping to grids of
>> various sizes, nothing seem to make it happy.  I'm trying to reduce the
>> amount of lines being unioned to see if that either fixes it or at least I
>> can get a small enough test case to post here.
>>
>>
>> On Tue, Jul 27, 2010 at 10:59 AM, Jeff Adams <jadams at azavea.com> wrote:
>>
>>     
>>> The challenge is I don't know the exact point it is unhappy about.  If
>>> I check the one in the error message, none of my linestrings intersect
>>> it, which means it is probably being printed with insufficient
>>> precision.  I have 19 linestrings that have a point that could be
>>> printed as -118.296 34.1185 due to rounding.
>>>
>>> Also, the two linestrings printed in the error aren't real inputs,
>>> they must be something created internally by ST_Union as it is
>>> processing.
>>>
>>> I tried adding a ST_SnapToGrid(..., 0.00001)  (0.00001 is very roughly
>>> a meter in lat/lon) and it has been running for almost 40 minutes, so
>>> it is either slower than before or it has made it further than before
>>> :-).
>>>
>>> Jeff
>>>
>>> On Tue, Jul 27, 2010 at 10:27 AM, Nicolas Ribot <nicolas.ribot at gmail.com>
>>> wrote:
>>>       
>>>>> ST_IsValid returns true for all of them.  I'll try reducing the
>>>>> precision slightly, though I'm later going to do point-in-poly checks
>>>>> against some other original input data and the reduced precision will
>>>>> increase the chances of inaccurate results.
>>>>>
>>>>>           
>>>> Ok,
>>>> I'm wondering if using the notice message could be used in conjunction
>>>> with linear referencing functions to add the missing point to the
>>>> failing linestring(s):
>>>>
>>>> 1- identify failing linestrings (or offending coordinates, then
>>>> finding the closest linestring to this point)
>>>> 2- complete these linestrings with new points built from coordinates
>>>> 3- relaunch the union procedure.
>>>>
>>>> Though I've never done this.
>>>>
>>>> Nicolas
>>>> _______________________________________________
>>>> postgis-users mailing list
>>>> postgis-users at postgis.refractions.net
>>>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>>>>
>>>>         
>>     
>
>   
> ------------------------------------------------------------------------
>
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> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>   

-- 
Martin Davis
Senior Technical Architect
Refractions Research, Inc.
(250) 383-3022