Take the 2-minute tour ×
Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

I have a polygon defined as follows:

segment from 43:29:02 N 003:50:39 E to 43:34:12 N 003:43:04 E arc(CW): center (43:34:49 N 003:58:16 E) from 43:34:12 N 003:43:04 E to 43:45:45 N 003:59:56 E segment from 43:45:45 N 003:59:56 E to 43:40:01 N 004:06:40 E arc(CCW): center(43:34:49 N 003:58:16 E) from 43:40:01 N 004:06:40 E to 43:29:02 N 003:50:39 E

The corresponding shapefile can be found at http://bordel.kataplop.net/mont2.zip

EDIT corresponding WKT:

POLYGON ((3.8441666666666667 43.4838888888888917, 3.7177777777777781 43.5700000000000003,3.7177777777777781 43.5700000000000003, 3.7175416922400166 3.5735823218689617, 3.7174122630334763 43.5767891717197671, 3.7173600981542299 3.5799971695780499, 3.7173852258405691 43.5832053383720393, 3.7174876507934393 3.5864127008216897, 3.7176673541599534 43.5896182797364418, 3.7179242935240802 3.5928210983129603, 3.7182584029045262 43.5960201804331646, 3.7186695927598370 3.5992145509620244, 3.7191577500007265 43.6024032360454115, 3.7197227380096543 3.6055852634076615, 3.7203643966676592 43.6087596626488931, 3.7210825423884666 3.6119254655418658, 3.7218769681598638 43.6150817063284819, 3.7227474435923660 3.6182274220155932, 3.7236937149751603 43.6213616526702097, 3.7247155053393355 3.6244834417140126, 3.7258125145283985 43.6275918362168653, 3.7269844192760679 3.6306858871895287, 3.7282308732913374 43.6337646498753315, 3.7295515073508057 3.6368271840406265, 3.7309459293982550 43.6398725542641515, 3.7324137246514693 3.6428998302249624, 3.7339544557162703 43.6459080869891309, 3.7355676627077550 3.6488964052947779, 3.7372528633787132 43.6518638718357153, 3.7390095532552006 3.6548095795431905, 3.7408372057792332 43.6577326278661104, 3.7427352724585923 3.6606321230492824, 3.7447031830236801 43.6635071784097093, 3.7467403455914190 3.6663569146109367, 3.7488461468361369 43.6691804599352409, 3.7510199521674097 3.6719769505535709, 3.7532611059148122 43.6747455307932810, 3.7555689315195373 3.6774853534034406, 3.7579427317328289 43.6801955798176920, 3.7603817888211850 3.6828753804145080, 3.7628853647782754 43.6855239347749134, 3.7654527015435106 3.6881404319373985, 3.7680830212272212 43.6907240706500630, 3.7707755263423635 3.6932740596198741, 3.7735294000427100 43.6957896177589262, 3.7763438063674428 3.6982699744277099, 3.7792178904920881 43.7007143696751754, 3.7821507789857174 3.7031220544756636, 3.7851415800743458 43.7054922909624679, 3.7881893839104470 3.7078243526580579, 3.7912932628485052 43.7101175247009124, 3.7944522717265268 3.7123711040687439, 3.7976654481534204 43.7145843997981558, 3.8009318128021703 3.7167567332007110, 3.8042503697087033 43.7188874380751002, 3.8076201065763597 3.7209758609156580, 3.8110399950858844 43.7230213611168708, 3.8145089912108232 3.7250233111740272, 3.8180260355382507 43.7269810968797614, 3.8215900535947016 3.7288941175165959, 3.8251999561772285 43.7307617860452567, 3.8288546396894598 3.7325835292888101, 3.8325529864825651 43.7343587881124947, 3.8362938652010095 3.7360870175992957, 3.8400761311329896 43.7377676872209449, 3.8438986265654367 3.7394002810046700, 3.8477601811434705 43.7409842976952632, 3.8516596122341884 3.7425192509126504, 3.8555957252946604 43.7440046693048501, 3.8595673142440319 3.7454400966961998, 3.8635731618395748 43.7468250922308997, 3.8676120400566001 3.7481592305117388, 3.8716827104720783 43.7494421017339974, 3.8757839246518482 3.7506733118145732, 3.8799144245412855 43.7518524825160000, 3.8840729428592957 3.7529792515656695, 3.8882582034955018 43.7540532727700295, 3.8924689219104849 3.7550742161236030, 3.8967038055389538 43.7560417679131319, 3.9009615541956921 3.7569556308164564, 3.9052408604841538 43.7578155239962783, 3.9095404102075606 3.7586211831888079, 3.9138588827823697 43.7593723607871041, 3.9181949516539527 3.7600688259191912, 3.9225472847143648 43.7607103645209961, 3.9269145447220355 3.7612967794038497, 3.9312953897232594 43.7618278903168019, 3.9356884734753175 3.7623035340034718, 3.9400924458711075 43.7627235642536689, 3.9445059533651090 3.7630878519495354, 3.9489276394005572 43.7633962851063103, 3.9533561448376653 3.7636487689077285, 3.9577901083827460 43.7638452257359774, 3.9622281670180910 3.7639855951961891, 3.9666689564324482 43.7640698341355332, 3.9711111114519491 3.7640979166568798, 3.9755532664713464 43.7640698341269285, 3.9799940558853892 3.7639855951789798, 3.9844321145202120 43.7638452257101846, 3.9888660780645604 3.7636487688733453, 3.9932945835007279 43.7633962850633438, 3.9988888888888892 3.7625000000000028, 3.9988888888888892 43.7625000000000028, 4.1111111111111107 3.6669444444444395, 4.1111111111111107 43.6669444444444395, 4.1081112312987518 3.6694234695150385, 4.1059413722282461 43.6711419317362726, 4.1037302561558127 3.6728326982839690, 4.1014785562310649 43.6744952517733864, 4.0991869581943616 3.6761290834102880, 4.0968561601681621 43.6777336931488875, 4.0944868724443211 3.6793085898469968, 4.0920798172674075 43.6808532914185932, 4.0896357286140903 3.6823673249835380, 4.0871553519686730 43.6838502270144886, 4.0846394440948499 3.6853015434809535, 4.0820887728037327 43.6867208299904419, 4.0795041167182582 3.6881076519267424, 4.0768862650339983 43.6894615845849543, 4.0742360172765091 3.6907822133038266, 4.0715541830552358 43.6920691335946785, 4.0688415818141008 3.6933219512673716, 4.0660990425788137 43.6945402825530920, 4.0633274037010221 3.6957237542238488, 4.0605275125993510 43.6968720037087905, 4.0577002254974373 3.6979846792071598, 4.0548464071590304 43.6990614397979940, 4.0519669306202575 3.7001019555463870, 4.0490626769191227 43.7011059076063972, 4.0461345348223459 3.7020729883204879, 4.0431834005496210 43.7030029013155357, 4.0402101774953803 3.7038953615952721, 4.0372157759481668 43.7047500956292794, 4.0342011128077022 3.7055668414383405, 4.0311671112997329 43.7063453486762228, 4.0281147006887696 3.7070853787079088, 4.0250448159887977 43.7077867046840609, 4.0219583976720550 3.7084491116119267, 4.0188563913759925 43.7090723964224779, 4.0157397476084853 3.7096563680338832, 4.0126094214514216 43.7102008474111940, 4.0094663722627448 3.7107056676222996, 4.0063115633770714 43.7111706738901589, 4.0031459618049512 3.7115957236411106, 3.9999705379309152 43.7119806865494525, 3.9967862652103707 3.7123254445782763, 3.9935941198654712 43.7126298920162455, 3.9903950805800497 3.7128939355107562, 3.9871901281937285 43.7131174940970979, 3.9839802453953022 3.7133004992237275, 3.9807664164154883 43.7134428947737987, 3.9775496267191737 3.7135446370826486, 3.9743308626972342 43.7136056949514540, 3.9711111113580424 3.7136260496570372, 3.9678913600187755 43.7136056949576854, 3.9646725959966083 3.7135446370951186, 3.9614558062999161 43.7134428947925002, 3.9582419773195738 3.7133004992486534, 3.9550320945204667 43.7131174941282339, 3.9518271421333155 3.7128939355481165, 3.9486281028469135 43.7126298920597947, 3.9454359575008815 3.7123254446280072, 3.9422516847790567 43.7119806866053580, 3.9390762609035903 3.7115957237031481, 3.9359106593298914 43.7111706739583425, 3.9327558504424895 3.7107056676965939, 3.9296128012519382 43.7102008474915635, 3.9264824750928522 3.7096563681203136, 3.9233658313231752 43.7090723965149621, 3.9202638250247972 3.7084491117104150, 3.9171774067055947 43.7077867047885249, 3.9141075220030173 3.7070853788183129, 3.9110551113893059 43.7063453487925457, 3.9080211098784452 3.7055668415605325, 3.9050064467349470 43.7047500957573263, 3.9020120451845597 3.7038953617291099, 3.8990388221270043 43.7030029014551289, 3.8960876878508262 3.7020729884658010, 3.8931595457504589 43.7011059077573663, 3.8902552920455964 3.7001019557029906, 3.8873758155029599 43.6990614399601753, 3.8845219971605558 3.6979846793748692, 3.8816947100545103 43.6968720038819711, 3.8788948189485768 3.6957237544024579, 3.8761231800663918 43.6945402827370586, 3.8733806408265834 3.6933219514566531, 3.8706680395807975 43.6920691337892180, 3.8679862053547485 3.6907822135035673, 3.8653359575923583 43.6894615847898251, 3.8627181059030749 3.6881076521366793, 3.8601334498124533 43.6867208302053953, 3.8575827785160706 3.6853015437008381, 3.8550668706368625 43.6838502272392475, 3.8525864939859447 3.6823673252131073, 3.8501424053270101 43.6808532916528804, 3.8477353501443670 3.6793085900859452, 3.8453660624146853 43.6777336933924261, 3.8430352643825345 3.6761290836583598, 3.8407436663397725 43.6744952520258849, 3.8384919664088604 3.6728326985408302, 3.8362808503301578 43.6711419319974112, 3.8341109912532807 3.6694234697803836, 3.8319830495325728 43.6676778377045736, 3.8298976725267480 3.6659055698518159, 3.8278554944027792 43.6641072084053476, 3.8258571359440796 3.6622833034818925, 3.8239032043630350 43.6604344129611803, 3.8219942931179487 3.6585611023132358, 3.8201309817344384 43.6566639444233147, 3.8183138356313546 3.6547435194146729, 3.8165434059512564 43.6528004144691408, 3.8148202293954965 3.6508352236455082, 3.8131448280639657 43.6488485476959980, 3.8115177092995394 3.6468409938806090, 3.8099393655372626 43.6448131757796389, 3.8084102741583297 3.6427657131041897, 3.8069308973488800 43.6406992315050104, 3.8055016819636593 3.6386143623794922, 3.8041230593945863 43.6365117426770084, 3.8027954454442381 3.6343920147025415, 3.8015192402043150 43.6322558259189250, 3.8002948279390880 3.6301038287473517, 3.7991225769738843 43.6279366803666306, 3.7980028395886105 3.6257550425109812, 3.7969359519163612 43.6235595812664769, 3.7959222338471279 3.6213509668663235, 3.7949619889366235 43.6191298734849511, 3.7940555043202560 3.6168969790308338, 3.7932030506322558 43.6146529649385144, 3.7924048819299858 3.6123985159593701, 3.7916612356234385 43.6101343199516833, 3.7909723324099347 3.6078610676696670, 3.7903383762140490 43.6055794525518365, 3.7897595541327438 3.6032901705085649, 3.7892360363857511 43.6009939197090617, 3.7887679762711817 3.5986914003676489, 3.7883555101263844 43.5963833145296107, 3.7879987572940457 3.5940703658565170, 3.7876978200935398 43.5917532594112060, 3.7874527837975256 3.5894327014423624, 3.7872637166137779 43.5871093991689307, 3.7871306696722700 3.5847840605642105, 3.7870536770174819 43.5824573941399649, 3.7870327556059387 3.5801301087303372, 3.7870679053089629 43.5778029132758391, 3.7871591089206373 3.5754765166073952, 3.7873063321709624 43.5731516272305015, 3.7875095237441907 3.5708289531096042, 3.7877686153023324 43.5685092014527555, 3.7880835215138080 3.5661930784965250, 3.7884541400872318 43.5638812892914302, 3.7888803518103069 3.5615745374877150, 3.7893620205938126 43.5592735251216610, 3.7898989935206520 3.5569789524026021, 3.7904911008999558 43.5546915175004443, 3.7911381563261894 3.5524119163339805, 3.7918399567432615 43.5501408423599798, 3.7925962825135917 3.5478789863630809, 3.7934068974921065 43.5456270362466569, 3.7942715491051477 3.5433856768245562, 3.7951899684342383 43.5411555896139717, 3.7961618703046902 3.5389374526292983, 3.7971869533790148 43.5367319401772264, 3.7982649002550923 3.5345397226530011, 3.7993953775690708 43.5323614663379459, 3.8005780361029542 3.5301978331983648, 3.8018125108968346 43.5280494806857661, 3.8030984213657404 3.5259170615385997, 3.8044353714210359 43.5238012235854583, 3.8058229495963545 3.5217026095498341, 3.8072607291780023 43.5196218568565456, 3.8087482683397917 3.5175595974398064, 3.8102851102822637 43.5155164575530122, 3.8118707833762437 3.5134930575803338, 3.8135048013106849 43.5114900118501922, 3.8151866632447473 3.5095079284505033, 3.8169158539640686 43.5075474090460617, 3.8186918440411657 3.5056090486977283, 3.8205140899999148 43.5036934356838216, 3.8223820344840700 3.5018011513235479, 3.8242951064297430 43.4999327698025624, 3.8262527212418074 3.4980888580008198, 3.8282542809741620 43.4962699753225621, 3.8302991745138009 3.4944766735287303, 3.8323867777686216 43.4927094965716705, 3.8345164538589263 3.4909689804321928, 3.8366875533125495 43.4892556529591516, 3.8388994142635458 3.4875700337114921, 3.8411513626543869 43.4859126338027835, 3.8441666666666667 3.4838888888888917))

I'm using shapely to handle my data, and it reports that this polygon is self intersecting. I checked with QGis (it is also complaining about this problem), and I don't see why it would be self-intersecting.

I've narrowed down the problem to the 2 "single points" of the second arc (beginning and end). It looks like the 2 segments are considered as crossing the second arc... Which is not true. I'm not producing the data but I can ask for fixing it in case it is wrong. But in this case, I don't understand the problem (if any).

Is this an issue of some buggy python library (shared by shapely and qgis) or is it something else ?

share|improve this question
    
Following this gis.stackexchange.com/questions/1060/… I tried the buffer(0.000001) trick. This solved one of the problem (the example above). Unfortunately, for one other similar problem (looks very similar with the singular point at the extremity of an arc), the buffered polygon is completely changed (it ends up flat). –  Marc Feb 9 '11 at 18:03
add comment

3 Answers

up vote 7 down vote accepted

If I zoom in here...

enter image description here

I see this:

enter image description here

I think the issue stems from the limitation that a shapefile cannot store arcs. Instead it does a linear approximation. When a polyline intersects (what is intended to be) a circular arc at a tangent the zig zag approximation results in an intersection.

I'd recommend storing the geometry in something that supports circular arcs, like a file geodatabase. There is an open source API available for it. File Geodatabase Open API? When?

share|improve this answer
    
+1 Good analysis. But concerning the proposed solution, see my reply. –  whuber Feb 9 '11 at 18:50
    
thanks... It looks like I did not zoom enough ! As for the database, I can live with approximate arc (linestring), I don't need that much precision. I simply need to write something to fix bad geometry like this one. –  Marc Feb 9 '11 at 21:00
    
Maybe treat it as a multipolygon, then delete all but the largest polygon. –  Kirk Kuykendall Feb 9 '11 at 21:02
add comment

There is something strange about the specification of this polygon. The first arc has parameters

center (43:34:49 N 003:58:16 E) from 43:34:12 N 003:43:04 E to 43:45:45 N 003:59:56 E

These have decimal coordinates {3.971111111, 43.58027778}, {3.717777778, 43.57}, and {3.998888889, 43.7625}, respectively. The Haversine formula for spherical distances says the distance from the first point to the center is 0.232751 radians whereas the distance from the second point to the center is 0.14124 radians. Because those distances are different, the specified arc cannot exist. (If such a specification makes sense to some software, it must be applying an idiosyncratic interpretation. I would be interested in knowing what that interpretation is.)

share|improve this answer
    
I will add a check for this kind of error and notify the author of the original data ! I did not think of this check, thanks ! –  Marc Feb 9 '11 at 21:01
add comment

Well it displays in UDiG though whether this indicates validity I'm not sure. For any one wanting to check the WKT is:

MULTIPOLYGON (((3.8441666666666667 43.48388888888889, 3.717777777777778 43.57, 3.717777777777778 43.57, 3.7175416922400166 43.57358232186896, 3.7174122630334763 43.57678917171977, 3.71736009815423 43.57999716957805, 3.717385225840569 43.58320533837204, 3.7174876507934393 43.58641270082169, 3.7176673541599534 43.58961827973644, 3.71792429352408 43.59282109831296, 3.7182584029045262 43.596020180433165, 3.718669592759837 43.599214550962024, 3.7191577500007265 43.60240323604541, 3.7197227380096543 43.60558526340766, 3.720364396667659 43.60875966264889, 3.7210825423884666 43.611925465541866, 3.721876968159864 43.61508170632848, 3.722747443592366 43.61822742201559, 3.7236937149751603 43.62136165267021, 3.7247155053393355 43.62448344171401, 3.7258125145283985 43.627591836216865, 3.726984419276068 43.63068588718953, 3.7282308732913374 43.63376464987533, 3.7295515073508057 43.63682718404063, 3.730945929398255 43.63987255426415, 3.7324137246514693 43.64289983022496, 3.7339544557162703 43.64590808698913, 3.735567662707755 43.64889640529478, 3.737252863378713 43.651863871835715, 3.7390095532552006 43.65480957954319, 3.740837205779233 43.65773262786611, 3.7427352724585923 43.66063212304928, 3.74470318302368 43.66350717840971, 3.746740345591419 43.66635691461094, 3.748846146836137 43.66918045993524, 3.7510199521674097 43.67197695055357, 3.753261105914812 43.67474553079328, 3.7555689315195373 43.67748535340344, 3.757942731732829 43.68019557981769, 3.760381788821185 43.68287538041451, 3.7628853647782754 43.68552393477491, 3.7654527015435106 43.6881404319374, 3.768083021227221 43.69072407065006, 3.7707755263423635 43.693274059619874, 3.77352940004271 43.695789617758926, 3.776343806367443 43.69826997442771, 3.779217890492088 43.700714369675175, 3.7821507789857174 43.703122054475664, 3.7851415800743458 43.70549229096247, 3.788189383910447 43.70782435265806, 3.791293262848505 43.71011752470091, 3.7944522717265268 43.712371104068744, 3.7976654481534204 43.714584399798156, 3.8009318128021703 43.71675673320071, 3.8042503697087033 43.7188874380751, 3.8076201065763597 43.72097586091566, 3.8110399950858844 43.72302136111687, 3.814508991210823 43.72502331117403, 3.8180260355382507 43.72698109687976, 3.8215900535947016 43.728894117516596, 3.8251999561772285 43.73076178604526, 3.82885463968946 43.73258352928881, 3.832552986482565 43.734358788112495, 3.8362938652010095 43.736087017599296, 3.8400761311329896 43.737767687220945, 3.8438986265654367 43.73940028100467, 3.8477601811434705 43.74098429769526, 3.8516596122341884 43.74251925091265, 3.8555957252946604 43.74400466930485, 3.859567314244032 43.7454400966962, 3.8635731618395748 43.7468250922309, 3.8676120400566 43.74815923051174, 3.8716827104720783 43.749442101734, 3.875783924651848 43.75067331181457, 3.8799144245412855 43.751852482516, 3.8840729428592957 43.75297925156567, 3.8882582034955018 43.75405327277003, 3.892468921910485 43.7550742161236, 3.896703805538954 43.75604176791313, 3.900961554195692 43.75695563081646, 3.9052408604841538 43.75781552399628, 3.9095404102075606 43.75862118318881, 3.9138588827823697 43.759372360787104, 3.9181949516539527 43.76006882591919, 3.9225472847143648 43.760710364520996, 3.9269145447220355 43.76129677940385, 3.9312953897232594 43.7618278903168, 3.9356884734753175 43.76230353400347, 3.9400924458711075 43.76272356425367, 3.944505953365109 43.763087851949535, 3.9489276394005572 43.76339628510631, 3.9533561448376653 43.76364876890773, 3.957790108382746 43.76384522573598, 3.962228167018091 43.76398559519619, 3.966668956432448 43.76406983413553, 3.971111111451949 43.76409791665688, 3.9755532664713464 43.76406983412693, 3.9799940558853892 43.76398559517898, 3.984432114520212 43.763845225710185, 3.9888660780645604 43.763648768873345, 3.993294583500728 43.763396285063344, 3.998888888888889 43.7625, 3.998888888888889 43.7625, 4.111111111111111 43.66694444444444, 4.111111111111111 43.66694444444444, 4.108111231298752 43.66942346951504, 4.105941372228246 43.67114193173627, 4.103730256155813 43.67283269828397, 4.101478556231065 43.674495251773386, 4.099186958194362 43.67612908341029, 4.096856160168162 43.67773369314889, 4.094486872444321 43.679308589847, 4.0920798172674075 43.68085329141859, 4.08963572861409 43.68236732498354, 4.087155351968673 43.68385022701449, 4.08463944409485 43.68530154348095, 4.082088772803733 43.68672082999044, 4.079504116718258 43.68810765192674, 4.076886265033998 43.689461584584954, 4.074236017276509 43.69078221330383, 4.071554183055236 43.69206913359468, 4.068841581814101 43.69332195126737, 4.066099042578814 43.69454028255309, 4.063327403701022 43.69572375422385, 4.060527512599351 43.69687200370879, 4.057700225497437 43.69798467920716, 4.05484640715903 43.699061439797994, 4.0519669306202575 43.70010195554639, 4.049062676919123 43.7011059076064, 4.046134534822346 43.70207298832049, 4.043183400549621 43.703002901315536, 4.04021017749538 43.70389536159527, 4.037215775948167 43.70475009562928, 4.034201112807702 43.70556684143834, 4.031167111299733 43.70634534867622, 4.02811470068877 43.70708537870791, 4.025044815988798 43.70778670468406, 4.021958397672055 43.70844911161193, 4.0188563913759925 43.70907239642248, 4.015739747608485 43.70965636803388, 4.012609421451422 43.710200847411194, 4.009466372262745 43.7107056676223, 4.006311563377071 43.71117067389016, 4.003145961804951 43.71159572364111, 3.999970537930915 43.71198068654945, 3.9967862652103707 43.712325444578276, 3.993594119865471 43.712629892016245, 3.9903950805800497 43.712893935510756, 3.9871901281937285 43.7131174940971, 3.983980245395302 43.71330049922373, 3.9807664164154883 43.7134428947738, 3.9775496267191737 43.71354463708265, 3.9743308626972342 43.713605694951454, 3.9711111113580424 43.71362604965704, 3.9678913600187755 43.713605694957685, 3.9646725959966083 43.71354463709512, 3.961455806299916 43.7134428947925, 3.958241977319574 43.71330049924865, 3.9550320945204667 43.713117494128234, 3.9518271421333155 43.71289393554812, 3.9486281028469135 43.712629892059795, 3.9454359575008815 43.71232544462801, 3.9422516847790567 43.71198068660536, 3.9390762609035903 43.71159572370315, 3.9359106593298914 43.71117067395834, 3.9327558504424895 43.710705667696594, 3.9296128012519382 43.71020084749156, 3.926482475092852 43.709656368120314, 3.923365831323175 43.70907239651496, 3.920263825024797 43.708449111710415, 3.9171774067055947 43.707786704788525, 3.9141075220030173 43.70708537881831, 3.911055111389306 43.706345348792546, 3.908021109878445 43.70556684156053, 3.905006446734947 43.704750095757326, 3.9020120451845597 43.70389536172911, 3.8990388221270043 43.70300290145513, 3.896087687850826 43.7020729884658, 3.893159545750459 43.701105907757366, 3.8902552920455964 43.70010195570299, 3.88737581550296 43.699061439960175, 3.884521997160556 43.69798467937487, 3.8816947100545103 43.69687200388197, 3.878894818948577 43.69572375440246, 3.876123180066392 43.69454028273706, 3.8733806408265834 43.69332195145665, 3.8706680395807975 43.69206913378922, 3.8679862053547485 43.69078221350357, 3.8653359575923583 43.689461584789825, 3.862718105903075 43.68810765213668, 3.8601334498124533 43.686720830205395, 3.8575827785160706 43.68530154370084, 3.8550668706368625 43.68385022723925, 3.8525864939859447 43.68236732521311, 3.85014240532701 43.68085329165288, 3.847735350144367 43.679308590085945, 3.8453660624146853 43.677733693392426, 3.8430352643825345 43.67612908365836, 3.8407436663397725 43.674495252025885, 3.8384919664088604 43.67283269854083, 3.8362808503301578 43.67114193199741, 3.8341109912532807 43.669423469780384, 3.831983049532573 43.667677837704574, 3.829897672526748 43.665905569851816, 3.827855494402779 43.66410720840535, 3.8258571359440796 43.66228330348189, 3.823903204363035 43.66043441296118, 3.8219942931179487 43.658561102313236, 3.8201309817344384 43.656663944423315, 3.8183138356313546 43.65474351941467, 3.8165434059512564 43.65280041446914, 3.8148202293954965 43.65083522364551, 3.8131448280639657 43.648848547696, 3.8115177092995394 43.64684099388061, 3.8099393655372626 43.64481317577964, 3.8084102741583297 43.64276571310419, 3.80693089734888 43.64069923150501, 3.8055016819636593 43.63861436237949, 3.8041230593945863 43.63651174267701, 3.802795445444238 43.63439201470254, 3.801519240204315 43.632255825918925, 3.800294827939088 43.63010382874735, 3.7991225769738843 43.62793668036663, 3.7980028395886105 43.62575504251098, 3.7969359519163612 43.62355958126648, 3.795922233847128 43.62135096686632, 3.7949619889366235 43.61912987348495, 3.794055504320256 43.616896979030834, 3.793203050632256 43.614652964938514, 3.792404881929986 43.61239851595937, 3.7916612356234385 43.61013431995168, 3.7909723324099347 43.60786106766967, 3.790338376214049 43.60557945255184, 3.789759554132744 43.603290170508565, 3.789236036385751 43.60099391970906, 3.7887679762711817 43.59869140036765, 3.7883555101263844 43.59638331452961, 3.7879987572940457 43.59407036585652, 3.78769782009354 43.591753259411206, 3.7874527837975256 43.58943270144236, 3.787263716613778 43.58710939916893, 3.78713066967227 43.58478406056421, 3.787053677017482 43.582457394139965, 3.7870327556059387 43.58013010873034, 3.787067905308963 43.57780291327584, 3.7871591089206373 43.575476516607395, 3.7873063321709624 43.5731516272305, 3.7875095237441907 43.570828953109604, 3.7877686153023324 43.568509201452756, 3.788083521513808 43.566193078496525, 3.788454140087232 43.56388128929143, 3.788880351810307 43.561574537487715, 3.7893620205938126 43.55927352512166, 3.789898993520652 43.5569789524026, 3.790491100899956 43.554691517500444, 3.7911381563261894 43.55241191633398, 3.7918399567432615 43.55014084235998, 3.7925962825135917 43.54787898636308, 3.7934068974921065 43.54562703624666, 3.7942715491051477 43.543385676824556, 3.7951899684342383 43.54115558961397, 3.79616187030469 43.5389374526293, 3.797186953379015 43.536731940177226, 3.7982649002550923 43.534539722653, 3.7993953775690708 43.532361466337946, 3.800578036102954 43.530197833198365, 3.8018125108968346 43.528049480685766, 3.8030984213657404 43.5259170615386, 3.804435371421036 43.52380122358546, 3.8058229495963545 43.521702609549834, 3.8072607291780023 43.519621856856546, 3.8087482683397917 43.517559597439806, 3.8102851102822637 43.51551645755301, 3.8118707833762437 43.513493057580334, 3.813504801310685 43.51149001185019, 3.8151866632447473 43.5095079284505, 3.8169158539640686 43.50754740904606, 3.8186918440411657 43.50560904869773, 3.820514089999915 43.50369343568382, 3.82238203448407 43.50180115132355, 3.824295106429743 43.49993276980256, 3.8262527212418074 43.49808885800082, 3.828254280974162 43.49626997532256, 3.830299174513801 43.49447667352873, 3.8323867777686216 43.49270949657167, 3.8345164538589263 43.49096898043219, 3.8366875533125495 43.48925565295915, 3.8388994142635458 43.48757003371149, 3.841151362654387 43.48591263380278, 3.8441666666666667 43.48388888888889)))
share|improve this answer
    
I think your exporting tool changed something, it should be POLYGON, I updated the question –  Marc Feb 9 '11 at 18:14
    
mine is just a multipolygon with one polygon in it. –  iant Feb 9 '11 at 20:39
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.