Question

Lorsque vous avez une table avec un champ de type géométrique (ou géographie), vous pouvez appeler la fonction Reduce() d'avoir les formes réduites en nombre de sommets. Fonctionne très bien. Toutefois, lorsque sevral des polygones sont adjacents (ils partagent une partie de leurs frontières), les polygones réduits ne font pas nécessairement.

Exemple

Le lot SQL:

CREATE TABLE #Shapes (
shape geometry,
naam varchar(50)
 )

-- exact:
insert into #Shapes (naam, shape) VALUES ('Area A',Geometry::STGeomFromText('POLYGON ((52.084744368912652 5.1304192959796637, 52.085234231548384 5.1304194002877921, 52.085474282948049 5.1304486630822, 52.0857341082301 5.1304792705923319, 52.086134375073016 5.1306082883384079, 52.086594087770209 5.13079824927263, 52.087194303050637 5.1311187236569822, 52.089074697112665 5.1323992793913931, 52.089834430487826 5.1333390253130347, 52.090353938518092 5.1341692635323852, 52.090254480473 5.1342997345712416, 52.090824429301414 5.13520842681262, 52.09141399711384 5.1360295349486274, 52.091884278226644 5.1365492835175246, 52.092085719574243 5.1367767199408263, 52.092194211203605 5.1368992186617106, 52.092494247804545 5.1372492032188495, 52.092884057915427 5.13754907634854, 52.093083867570385 5.137679290259257, 52.093254011290028 5.1378082139755827, 52.093554640188813 5.1380093733314425, 52.094204571098089 5.1384683684445918, 52.094214495038614 5.1384888619650155, 52.093702809136488 5.1390791568504124, 52.0939114689827 5.1395669728517532, 52.0938675517682 5.1396009074524045, 52.093849835848111 5.1396084928439114, 52.093797143315896 5.1396473892964423, 52.093789743114428 5.1396500989447063, 52.093731224210721 5.13969055645838, 52.093728204024956 5.1396938753314316, 52.093717452138662 5.1397007238119841, 52.09355255169794 5.139717671321705, 52.093311328208074 5.1395945930853486, 52.093306955655407 5.1395602072316251, 52.093115365831181 5.1400826557073742, 52.093052050564438 5.1401469679549336, 52.092979203676805 5.1401289247442037, 52.092756105586886 5.1398569964803755, 52.092737412561 5.1397823067194368, 52.09235419591127 5.1398883965623128, 52.092214386788811 5.1400686172528616, 52.092164272349919 5.1401695687556135, 52.09208471653983 5.1403786691371351, 52.0920239102561 5.1405293103307486, 52.091924546519294 5.1407297900877893, 52.091534494888037 5.1407990844454616, 52.091654436912947 5.1401591910829172, 52.091713753540262 5.1397284107361845, 52.091763769509271 5.1391488309018314, 52.091774359305148 5.1390583129178058, 52.09170373348757 5.1383788494901648, 52.0907391263172 5.1386201300192624, 52.090711282333359 5.1385075189173222, 52.090718721970916 5.1384486802853644, 52.090745792724192 5.1383893731981516, 52.090758387919244 5.1383728119598793, 52.090776969445869 5.1383237342815846, 52.090780415022657 5.1383173598065737, 52.090745287947357 5.1382717578671873, 52.090742629869759 5.1382662602414895, 52.090704807080328 5.1382211977615952, 52.0906867091544 5.1381677808240056, 52.090701617482885 5.1380081428639635, 52.090564404382455 5.138029116065514, 52.09062412660569 5.1386488282587379, 52.090704361908138 5.1396187201607972, 52.09069472597912 5.1397384563460946, 52.090674098813906 5.1398086878471076, 52.090624484543433 5.1397491229489587, 52.090589968811038 5.1397359627815975, 52.090441891923547 5.140045978827402, 52.090305342804641 5.1400443047750741, 52.0902322656475 5.139729289803654, 52.090199632104486 5.1394877941347659, 52.090188750764355 5.1393666968215257, 52.0902532400633 5.1393868076773792, 52.09003754449077 5.1387802169192582, 52.090024582457204 5.1386965749382565, 52.090020758565515 5.1386840578634292, 52.0900124781623 5.1386172670806785, 52.090003480669111 5.1385827830526978, 52.08999918546494 5.1385372205978728, 52.089985796017572 5.1384773049503565, 52.089996868744493 5.1384535257238895, 52.090046249330044 5.138385351980105, 52.090212456043091 5.1382693609882955, 52.090183896290647 5.1379786310671935, 52.090166853580648 5.1378115779987894, 52.0899735938292 5.137785307597369, 52.089885840192437 5.1377143466379493, 52.08985487697646 5.137671007309109, 52.089845903217793 5.1376524229999632, 52.089844238944352 5.1376464897766709, 52.089850628050044 5.1375868958421052, 52.089852778393364 5.137576853302618, 52.089863699774533 5.1374888862706634, 52.089867451693863 5.1373642447870225, 52.089883847394958 5.1373361134901643, 52.089941705111414 5.1372730266302824, 52.090002277167514 5.1372403032146394, 52.090108146462811 5.1372361269295483, 52.09006458793673 5.1368091938053615, 52.089683820260689 5.1369396857917309, 52.089193989204269 5.1364887236994123, 52.088854428613558 5.1373995044268668, 52.088474480202422 5.1383894786704332, 52.088474343996495 5.1383894337341189, 52.088464433038652 5.1383690948872287, 52.088414154422111 5.13834898790222, 52.088394471909851 5.1383694768883288, 52.0883943233639 5.1383694719988853, 52.08832395415709 5.1382487505018526, 52.087933741509914 5.1377592226490378, 52.087544413445592 5.1372594955892383, 52.087484167695806 5.1372292107739481, 52.087364645209163 5.1372284211684018, 52.0869538753575 5.1372190437554366, 52.085683952551335 5.1372596949804574, 52.085304662585258 5.137269108556211, 52.085084051657141 5.1370588609653955, 52.084904317976907 5.137469710316509, 52.084444417446747 5.1384497439414369, 52.084454428168293 5.1385195698547266, 52.084484005579725 5.1385092278942466, 52.084537888644263 5.1385357407853007, 52.084511198022149 5.1389506391238067, 52.084534639492631 5.1391157133039087, 52.084215438459069 5.139372929232195, 52.084103818604156 5.1389697602953825, 52.083964082412422 5.1391396226827055, 52.083963935496286 5.139139630831778, 52.083883681101725 5.1390291205607355, 52.083994359437455 5.1386593720505784, 52.084013982437057 5.1385892418004318, 52.084053878448593 5.1383293403318735, 52.084054407430678 5.1377297231794907, 52.084053982747719 5.1375283871311694, 52.084063940448686 5.1371387927792966, 52.084070490673184 5.13703247718513, 52.084070608951151 5.1370323959272355, 52.084217049471441 5.1370617711960529, 52.0842700656977 5.1370595147110754, 52.084318579515468 5.1370449147663777, 52.084365648221834 5.137017846536426, 52.084410294202549 5.1369791406907863, 52.084451525192954 5.1369308069453, 52.084497402298688 5.1368615722581685, 52.084511263761669 5.1368357082828879, 52.084539652187722 5.1367929205345337, 52.084559679031372 5.1367565956898034, 52.084580525973493 5.1367251129565776, 52.0845936126653 5.1367018828692963, 52.084593039704487 5.1366802926640958, 52.084593520236 5.1366613829106731, 52.084592797560617 5.136602794053033, 52.0845930285151 5.1365417347624449, 52.084591784281656 5.1365062294062227, 52.084592622431977 5.1364672367903337, 52.084591892315075 5.1364289335906506, 52.084595442516729 5.13633631542325, 52.084596794845957 5.1363224481129421, 52.084599652094766 5.13625919749029, 52.084600140111739 5.1362545876124468, 52.084603969780289 5.1361925578721053, 52.084604394622147 5.1361672168131918, 52.084607248043845 5.1361305358165161, 52.084609296828042 5.13606852098146, 52.084609103156254 5.1360535530839115, 52.084611643842678 5.1360064989442122, 52.08461217648793 5.1359452261162533, 52.084612038685009 5.1359415214974433, 52.084614087827504 5.1358594063203782, 52.084640604443848 5.1355516116600484, 52.084642857778817 5.135543460957706, 52.084982043160878 5.1354961035347806, 52.085083917947486 5.1345288194715977, 52.085104202153161 5.1343492493033409, 52.08524441709433 5.1330996853375064, 52.085165794240311 5.1330994283780456, 52.085158604676472 5.1330777355575146, 52.084887840552256 5.1328501671087, 52.084870130718066 5.1327825202649118, 52.084810143569484 5.132734818616882, 52.084766256157309 5.1326845148578286, 52.084753367166229 5.1326649976350005, 52.084720281418413 5.1326657184399664, 52.084673544857651 5.1326567681971937, 52.084627489326522 5.13263783371076, 52.084616634761915 5.1326309095602483, 52.084607382304966 5.1326056816615164, 52.084589018020779 5.1325388213153929, 52.084566780831665 5.1324195361230522, 52.08455663616769 5.1322953840717673, 52.084555578185245 5.1322289216332138, 52.084558193339035 5.1321669477038085, 52.084565328201279 5.1320932512171566, 52.084573237691075 5.1320388016756624, 52.084590001497418 5.1319514436181635, 52.084614846622571 5.1318454830907285, 52.084674907008818 5.1317076328407039, 52.084733415627852 5.1315451303962618, 52.084768428234277 5.1314570531469457, 52.084772500442341 5.131445026723668, 52.084790059469135 5.1313976899708305, 52.084790684864267 5.1313653332182225, 52.084789962507784 5.1313581170979887, 52.084786229995423 5.1313093374080232, 52.084781658835709 5.1312665985897183, 52.084776584757492 5.131205978570506, 52.084776126593319 5.1311985920700378, 52.084773858077824 5.1311737054493278, 52.084770929767942 5.1311195062007151, 52.084764682454988 5.1310441740788519, 52.084762406875207 5.1310067452953634, 52.084759807214141 5.1309909871779382, 52.084745739819482 5.1308908765204251, 52.084737451048568 5.1308199469931424, 52.084731393493712 5.1307550501078367, 52.084726219235463 5.130682019587562, 52.084717591805187 5.130595849588774, 52.084696356672794 5.1304316397290677, 52.084744368912652 5.1304192959796637))', 1) );
insert into #Shapes (naam,  shape) VALUES ('Area B', Geometry::STGeomFromText('POLYGON ((52.089193944586441 5.1364884474314749, 52.089683880347387 5.1369394774090678, 52.090064640389755 5.1368089618626982, 52.090064767515287 5.13680902402848, 52.090108351781964 5.1372362461406738, 52.0900023451254 5.137240494616317, 52.089941830607358 5.1372731845887953, 52.089884013120034 5.1373362265352416, 52.089867649300196 5.13736428650584, 52.089863897534087 5.1374888976570219, 52.089852973818779 5.1375768855214119, 52.089850827719964 5.1375869208953633, 52.08984444080243 5.1376464707614575, 52.089846089016071 5.1376523461555816, 52.089855048116348 5.13767090524721, 52.089885986401136 5.1377142074887443, 52.089973680692943 5.137785122508185, 52.090167043032125 5.1378114717081189, 52.090184094849974 5.1379786091856658, 52.090212659211829 5.138269433286041, 52.090046387117965 5.1383854977954284, 52.089997038751484 5.1384536319841185, 52.089986001565585 5.1384773087642488, 52.0899993844796 5.138537187827751, 52.090003677353721 5.1385827515141784, 52.0900126749184 5.1386172289494425, 52.090020956756526 5.1386840232833055, 52.0900247762911 5.1386965326964855, 52.090037737332914 5.1387801609122805, 52.090253500966355 5.1393869426101446, 52.090253373142332 5.1393870580941439, 52.09018895904866 5.1393668668649326, 52.09019982968524 5.1394877681651483, 52.090232462748588 5.1397292593531256, 52.090305473417473 5.1400441225035083, 52.090441768325739 5.1400458008552627, 52.0905898406636 5.1397357748355716, 52.090624607168138 5.1397489595692605, 52.090674059544682 5.1398083794509937, 52.090694529374325 5.1397384163970843, 52.090704163346672 5.1396187301667995, 52.0906239267189 5.1386488468750029, 52.090564216952771 5.1380289690569043, 52.090701825218275 5.138007998932153, 52.090686907175666 5.1381677433547006, 52.090704979235063 5.1382210930865915, 52.090742795495316 5.13826614478603, 52.090745454392028 5.1382716438933382, 52.090780634433031 5.138317345874384, 52.090777151606311 5.1383238151729582, 52.090758565347642 5.1383729032240808, 52.090745967798135 5.1383894728374937, 52.090718918413778 5.1384487237036574, 52.09071148235433 5.1385074989634694, 52.090739235906476 5.1386199161658359, 52.091703911079094 5.1383786785881966, 52.091774561209604 5.1390583219472319, 52.091763966455993 5.1391488551129392, 52.091713952366263 5.1397284283302724, 52.091654634801671 5.1401592225302011, 52.091534660555041 5.1407988700928273, 52.091924405223438 5.1407296329252166, 52.092023730557614 5.1405292234111544, 52.092084533682055 5.1403785903667165, 52.092164086876437 5.1401694919914007, 52.092214212752879 5.1400685210246593, 52.092354092746973 5.1398882211651653, 52.092737518250942 5.1397820895072073, 52.092756280866688 5.1398568955139261, 52.092979332917338 5.1401287692562034, 52.093051998862443 5.14014675848039, 52.093115186976668 5.1400825616937738, 52.093306944705546 5.1395597066730261, 52.093307103263214 5.139559774659574, 52.093311476645688 5.1395944439214718, 52.093552575019729 5.1397174675798443, 52.093717376162488 5.1397005364784905, 52.093728081547653 5.1396937158987059, 52.093731097411364 5.1396904007997364, 52.093789641978219 5.1396499255206436, 52.09379703433958 5.139647218074332, 52.093849730910733 5.139608321711421, 52.0938674450952 5.1396007388582916, 52.093911277158938 5.13956686834194, 52.093702596845105 5.1390791060402989, 52.094214342534542 5.1384887341409922, 52.094234085874632 5.1384696427267045, 52.094364419566851 5.1384893088412067, 52.094364145770669 5.1383595434017479, 52.094394268468022 5.1381287302356213, 52.09443390479516 5.138148912037261, 52.094484106955747 5.1381194878988437, 52.094514668919146 5.1380682252347469, 52.094674076435417 5.1382088991813486, 52.095094393635229 5.1384881954232995, 52.0952940530714 5.1385585838544232, 52.095604252303019 5.1385889891535044, 52.095554116032766 5.1386696371579523, 52.095534724403237 5.1388492132525849, 52.095524277190037 5.1390082753444624, 52.095594465266913 5.1390487975440919, 52.095594199141487 5.1393494226504117, 52.09559461963309 5.1399783839006, 52.095604153974683 5.1410990775805754, 52.095644179129778 5.1413294123732438, 52.09575448022224 5.1416396433487535, 52.095824270925078 5.1419194503811445, 52.096084321906162 5.1429293346052836, 52.096143952025322 5.1430793148784755, 52.096264120657 5.1433793206233531, 52.096193926805284 5.1433798011214318, 52.096113997035054 5.14339920294765, 52.096024247104872 5.1434492955148228, 52.095944452364236 5.1435387324349744, 52.095874538511147 5.14362958598761, 52.095844099589421 5.143679338650661, 52.095844470186279 5.1438587997111922, 52.095854729064243 5.1440396906996444, 52.095894579105732 5.1441883100385768, 52.095964113250375 5.144369007088244, 52.09580374216273 5.144229786732418, 52.095674295010134 5.1441983953353239, 52.095563816432822 5.14421941922198, 52.095403983902024 5.1442888717546564, 52.095254029380158 5.1443597327452153, 52.094414402963594 5.1447291097138077, 52.094194360597214 5.1448091029165, 52.093554132385179 5.1451087987516075, 52.09298392268829 5.14536870829761, 52.092384074527615 5.1456389861371825, 52.091314621968991 5.1461291963244005, 52.091214230906282 5.1462493549551356, 52.091174073517323 5.1464188823010772, 52.0911739426665 5.146418813848868, 52.09113409327086 5.1462687528401041, 52.091084660668564 5.146199182483377, 52.091033940669149 5.1464488115161657, 52.090953806928624 5.1464084108564867, 52.090854425442245 5.1464496781230418, 52.089684411417693 5.1471287335734814, 52.0895846124041 5.1471190678897267, 52.088994233263378 5.1476095448153067, 52.088864096673205 5.1477386702317744, 52.088784483494237 5.1475289191585034, 52.088713807872537 5.1472491544173726, 52.088664193741309 5.1471487923554067, 52.088594123489734 5.1471287621828763, 52.088524112701435 5.1471597642893574, 52.088323859963566 5.1472586041782051, 52.088194384938106 5.1472490853630006, 52.088083737995476 5.147229231428355, 52.087984558660537 5.1470896604005247, 52.0871439545881 5.144788873847574, 52.086584153570342 5.1431184258301306, 52.086113808001116 5.1425490758657, 52.085764196002856 5.142129332292825, 52.085273851326242 5.1414594290601263, 52.084604130359367 5.1405483337584883, 52.08448414108716 5.1403388837352395, 52.084363697096705 5.1399091542698443, 52.084215331124142 5.1393728284165263, 52.084534444796994 5.1391156225659822, 52.084510998101905 5.1389506384730339, 52.084537685041475 5.1385358115798789, 52.084483979582181 5.1385094355204064, 52.084454281721264 5.138519779080525, 52.084444217151031 5.1384497005492449, 52.084904137838336 5.1374696237373572, 52.08508396637626 5.1370586035773158, 52.085304709049147 5.1372689084542849, 52.085683944402767 5.1372594968589222, 52.08695387118496 5.1372188439127058, 52.087364651495307 5.1372282228088277, 52.087484228890389 5.137229019543156, 52.087544555542991 5.1372593543492258, 52.087933897256818 5.1377590987963755, 52.088324117939919 5.1382486345246434, 52.088394418613781 5.138369242607296, 52.088414155179635 5.1383487726561725, 52.0884645585902 5.1383689332287759, 52.0884744236222 5.1383891381781037, 52.088854240353591 5.1373994332191018, 52.089193944586441 5.1364884474314749))', 1) );
insert into #Shapes (naam,  shape) VALUES ('Area C', Geometry::STGeomFromText('POLYGON ((52.081104027922265 5.1258389879949391, 52.081314665614627 5.1259588550310582, 52.082414517994039 5.1266395719721913, 52.082954646321014 5.1270186660112813, 52.083513987367041 5.127549389610067, 52.083794155623764 5.1278395495610312, 52.084174386574887 5.1282589976908639, 52.084274505455781 5.1284189013796713, 52.08453426125925 5.1288288246141747, 52.085124507819643 5.1299386160409242, 52.08521465482071 5.1300693768952019, 52.0853342462746 5.1301182725468744, 52.0854241597699 5.1300988405710086, 52.0854743384989 5.1304488354362547, 52.085234220619661 5.130419600171515, 52.084744388967557 5.1304194940048324, 52.08439406089019 5.1305090384557843, 52.083914360133932 5.1306285039224422, 52.083414051565342 5.1307787221157923, 52.082813916262239 5.13094844610896, 52.082724283281529 5.1306586048111562, 52.082483787322417 5.1300093204481527, 52.08225411306649 5.1293789464909949, 52.082194455789093 5.1292188489812043, 52.082134172902443 5.1291885531973094, 52.082084508962 5.1290896165883169, 52.082023798371665 5.1288696515839547, 52.081883911043406 5.1281993770971894, 52.081856097793207 5.12798699515406, 52.081856237724423 5.1279869175050408, 52.082000762340613 5.1280515332473442, 52.082027135184035 5.1280940270517021, 52.0820355968099 5.1281161647869, 52.08205282002023 5.1281410993754166, 52.08213594150827 5.1278323108932256, 52.0820438895719 5.1277594091965328, 52.081953932996839 5.1277496579568833, 52.081884289887846 5.1271693162703134, 52.081813924670755 5.1270196131258938, 52.081552422139794 5.1268787173321471, 52.08152364961375 5.1267665265884057, 52.081485387952739 5.1266524291002371, 52.081442847483068 5.1265567842247837, 52.081396028901857 5.1264795880384764, 52.081344932177927 5.1264208389159505, 52.081293396464417 5.1263833287749234, 52.081279310281388 5.1263776289997622, 52.081249886541627 5.1263603481929749, 52.081222431567454 5.12633884719625, 52.081221418222412 5.1263384295161813, 52.081197269726545 5.126324187265709, 52.081195053295232 5.1263138890499249, 52.081184833077714 5.1262332251062617, 52.0811841667945 5.1261982778874859, 52.081168951815926 5.1261331316782162, 52.081164751928249 5.1260440781433525, 52.081066497950815 5.1259329431923106, 52.081104027922265 5.1258389879949391))', 1) );
insert into #Shapes (naam,  shape) VALUES ('Area D', Geometry::STGeomFromText('POLYGON ((52.084103860426694 5.1389694481622428, 52.084363892148971 5.1399091025981294, 52.084484331319835 5.1403388143996294, 52.084604299141489 5.1405482272725367, 52.08527401345782 5.1414593127556145, 52.085764355740025 5.1421292096101565, 52.086113962111995 5.1425489480607212, 52.086584335425869 5.1431183374952525, 52.087144145466013 5.1447888108543749, 52.087984736636635 5.1470895681108679, 52.088083857744529 5.1472290623707631, 52.088194406595086 5.14724888795369, 52.088323822820605 5.1472584035787792, 52.088524032849818 5.14715958177112, 52.088594117900357 5.1471285563893616, 52.08866433496587 5.1471486398950219, 52.088713997742161 5.1472490890882909, 52.088784678140655 5.1475289016962051, 52.088534413350153 5.1477695436890123, 52.088604030199349 5.1479895326774567, 52.08846407078854 5.1481186849763318, 52.088304384844378 5.1482683648355305, 52.087993860917578 5.1484991029959017, 52.087834112113342 5.1486196045298129, 52.0874739959836 5.1487791088875383, 52.087183827068657 5.1488594498950988, 52.087034655727216 5.1488792099405627, 52.086844170233235 5.1489094072021544, 52.086553779430687 5.1488890685141087, 52.086283983197063 5.1488190072122961, 52.086004210880986 5.148699401849246, 52.085884556407109 5.148648968199268, 52.085783737245947 5.148579464526847, 52.085444359574467 5.1483186569530517, 52.08505431888625 5.147909271530807, 52.085063869832084 5.14774867403321, 52.085103993769735 5.1475894195027649, 52.085123664481678 5.1475485048696683, 52.084903807879783 5.1472594002206034, 52.084644382136524 5.1469792136778958, 52.08418409107253 5.1464885615278035, 52.0837237383239 5.1459687419701368, 52.083234543621856 5.145409702023275, 52.082664410911732 5.1448292277490495, 52.082063829526305 5.1443087360821664, 52.082091124779964 5.1440836547198483, 52.081992223858833 5.1440890550147742, 52.08196270884946 5.14405638189055, 52.081944186007604 5.1439888756722212, 52.08194406144986 5.1439872064089114, 52.08192484639585 5.1439289392437786, 52.081920254660311 5.1439031759941996, 52.081906982464716 5.1438652367796749, 52.081898384261621 5.143827152704362, 52.081886463514792 5.1437939475605585, 52.081860758494884 5.143810536588699, 52.081833417158236 5.1438379039788957, 52.081759569933638 5.14407270308584, 52.0816137263635 5.1439596123534246, 52.081454453474372 5.1438598307431391, 52.081304313847795 5.14384896773845, 52.080264462672268 5.1430187125121805, 52.079664091113955 5.1425989381968975, 52.079524534521624 5.14249899610877, 52.079534315969795 5.1424492821097374, 52.079674492839317 5.1419992103874552, 52.079703816364884 5.1418385940623406, 52.079714205814525 5.141648898134008, 52.079727753764018 5.1414623958989978, 52.080252137147674 5.1417998058748831, 52.08029427562046 5.1417563394152745, 52.080314928898588 5.1417286938522011, 52.0803562682122 5.1416860464960337, 52.080404439009726 5.1416505186352879, 52.080450373701751 5.1416298456024379, 52.080458209152553 5.1416284950795994, 52.080495744477957 5.141600257018581, 52.080541761592031 5.141581037081778, 52.080577370766676 5.1415776146752092, 52.080586124956035 5.1415745182313319, 52.080565002281219 5.1411468000151217, 52.080635850084946 5.1411388639826328, 52.081214110314008 5.1410789246463136, 52.081586783519015 5.1409964717458934, 52.081614242866635 5.1412574960850179, 52.081570835318416 5.1413511682767421, 52.08156742547277 5.1413547724810877, 52.081523078051127 5.1414396720759816, 52.081520885843375 5.1414458907124478, 52.0815235725604 5.1414493722841144, 52.081564587075263 5.1415304632391781, 52.081586116692051 5.1416122366208583, 52.081591385416651 5.1417623861789625, 52.081744097638875 5.1417384068481624, 52.081754462670077 5.14239915706246, 52.081888611945665 5.1424242914485125, 52.081887235166505 5.1422738104593009, 52.081907565006986 5.1422072551213205, 52.081948822597042 5.1421398329548538, 52.081990273194968 5.1420943139491024, 52.082000561989844 5.1420720012392849, 52.082041298272088 5.1420040489174426, 52.08205503895892 5.1419854623652519, 52.082057312844228 5.1419532595345077, 52.082057383609936 5.141936854692176, 52.082061406905325 5.1418724298121266, 52.082061399472877 5.1418698709458113, 52.082065169426741 5.1418023992023132, 52.08206505025737 5.1417857583146542, 52.082067978335544 5.1417265709023923, 52.082068552136519 5.1417210444026873, 52.08207146529282 5.1416510321596576, 52.082074348499624 5.1415691960222105, 52.082074102712795 5.1415587870869786, 52.082077217031589 5.141500341455882, 52.082077142713729 5.1414836310842942, 52.082064611044075 5.1414689618560345, 52.08204338257201 5.1414488023146987, 52.0820095549712 5.1414023755017455, 52.08195383178483 5.1413428048418419, 52.0819458400365 5.1413370133377612, 52.081897551489291 5.141270585100548, 52.081845151958987 5.1412304241675884, 52.081783577566966 5.1409387167077512, 52.082063805446388 5.1408189585007031, 52.082534100375206 5.1404983382591407, 52.082604082068428 5.1404395992867649, 52.082693810134288 5.1403690781753832, 52.083284175475136 5.1398683352445742, 52.083963928950048 5.1391394941752653, 52.084103860426694 5.1389694481622428))', 1) );

select naam, shape, shape.Reduce(0.001) as reducedShape from #Shapes

drop table #Shapes

retourne deux ensembles de polygones. Tout d'abord l'ensemble non réduite:

text alt

Ensuite, l'ensemble réduit:

text alt

Ces formes sont beaucoup plus simples et ils ont la forme approximative correcte, mais ce que je veux est d'avoir les frontières-parties encore partagées. Ils doivent donc être réduits ensemble, d'une manière.

Je pense que vous devez les diviser en polylignes premier (de bord à bord), puis réduire les lignes, puis les réassembler à nouveau polygones. Je ne sais pas comment faire cela dans T-SQL bien.

Toutes les idées?

Edit: Je l'ai accepté la réponse de alphadaogg. Les deux réponses actuelles ne sont pas entièrement covincing pour moi, mais alphadogg a certainement mis dans le plus gros effort et je l'apprécie vraiment tout partage de pensées. Ainsi, la prime va à lui.

Je vais suivre avec une auto-réponse plus tard si je trouve une méthode satisfaisante.

Suivi : J'envoyé par courriel avec Isaac Kunen, gestionnaire de programme de l'équipe SqlServer Geo. Sa réponse est helpfull ci-dessous:

  

Votre problème est pas rare, mais   ce n'est pas quelque chose que nous directement   soutien: il est une opération   exige une connaissance de la topologie   vos chiffres, et nous n'avons pas   quelque chose comme ça construit.   Essentiellement, vous ne voulez pas stocker   polygones séparés pour chaque   quartier. Au contraire, vous voulez   Les courbes de magasins représentant des parties de   limites et réutiliser ces limites   pour plusieurs polygones. Lorsque vous   généraliser, vous généralisez la commune   limite et tous les polygones dépendants   sont touchés.

     

Vous pouvez construire vous-même --- comme   affiches dans le fil que vous citez   indice --- mais il peut être réel effort à faire   ainsi.

     

Je ne sais pas le logiciel tiers   vous utilisez, mais c'est l'autre   option. Si vous ne voulez pas   SIG à part entière, vous pouvez utiliser un   paquet comme le FME de Safe   Logiciel ( http://www.safe.com ). le   FME ne fait pas usage général   topologie, mais je crois qu'il a assez   fonctionnalité pour faire ce que vous êtes   à la recherche de. Voir:    http://www.safe.com/products/desktop/ sous-la-hood.php # 3b .

     

J'espère que cette aide.

     

Cheers,

     

-Isaac

Était-ce utile?

La solution

Je ne sais pas comment vous obtiendrez les LineStrings « partagés » de vos formes. En second lieu, une fois que vous réduisez un « sous-ensemble » de la forme puisque vos extrémités peuvent passer de l'original et vous ne serez pas en mesure de les faire correspondre après réduction.

Le mot de ce que je ferais est d'utiliser essentiellement des opérations booléennes pour jouer avec les formes réduites.

D'abord, faites ce que vous faites, à savoir créer une table temporaire de formes réduites (appelées #ReducedShapes).

Alors, je voudrais créer une deuxième table temporaire et trouver les zones de chevauchement (à l'aide STIntersection) entre toutes les formes. Dans ce tableau, je essentiellement avoir des colonnes naam1, naam2 et intsec, le dernier étant de forme de type. Quelque chose comme (non testé):

INSERT INTO #IntSecs(naam1, naam2, intsec)
SELECT s1.naam, s2.naam, s1.naam.STIntersection(s2.naam)
FROM #ReducedShapes s1, #ReducedShapes s2 
WHERE s1.naam.STIntersection(s2.naam) IS NOT NULL

Cela vous obtient une liste des endroits où se chevauchent paires de formes. En fait, vous avez deux lignes pour chaque chevauchement. Par exemple, si A et B se chevauchent et que vous auriez. Je voudrais faire une passe et supprimer l'un des deux pour chaque occurence.

Enfin, pour chaque chevauchement, je soustraire (STDifference) l'intersection à partir de seulement l'une des deux régions dans la paire de la table de #ReducedShapes. Imaginez que vous avez deux places A et B, demi-chevauchement. L'opération impliquerait A.STDifference (B) qui signifie que vous gardez tous B et la moitié de A. J'insérer les formes modifiées dans une troisième table (disons #ModifiedShapes).

Deux problèmes: a) que vous pouvez voir à partir de votre « orange » et des formes « bleu », ils ne réduisaient pas de même, de sorte que vous aurez l'une des deux réductions possibles en fonction de la façon dont vous traitez avec qui « gagne ». b) une forme plus complexe du problème est que, en fonction de la complexité des formes initiales, vous pouvez obtenir un chevauchement entre les trois régions ou plus. Vous devrez déterminer votre propre façon d'établir une forme qui « gagne » dans cette intersection, en fonction de vos besoins particuliers. On ne sait pas s'il y a des contraintes. Peut-être aussi simple que de choisir arbitrairement un gagnant en ordonnant, ou plus complexe, car la précision est importante.

Le concept ci-dessus, malheureusement, ne traite pas de la question des lacunes. Celui-ci est un peu plus compliqué et je ne suis pas sûr à 100% comment le résoudre. Mais, si vous créez une troisième table qui retranche (STDifference nouveau) toutes les formes modifiées #ModifiedShapes de toutes les formes originales en #Shapes (test de chevauchement avant en fait la soustraction, bien sûr), vous seriez laissé avec les formes de reste dans les lacunes . Vous voudriez regrouper les formes voisines et attribuer une « couleur gagnante », peut-être fusionner en arrière avec la forme correspondante.

Cette réponse est longue et je vais le laisser comme ça. Je peux aboyer le mauvais arbre. Sur la base de vos commentaires / questions, je voudrais ajouter au poste.

Autres conseils

Wow, c'est un ensemble de fonctionnalités assez cool.

Jeter un oeil à quelques-unes des autres méthodes disponibles, voici quelques idées qui viennent à l'esprit:

Sur les formes non réduites, utilisez .STIntersects (retourne un booléen) et .STIntersection (retourne une forme) pour savoir si et où deux formes se croisent.

Pour deux régions adjacentes de la carte, je suppose que .STIntersection doit retourner le segment de ligne qui borde les deux.

Ensuite, vous pouvez réduire ces segments de ligne et réassembler les formes réduites.

Isaac est juste que vous pouvez réduire les caractéristiques des lignes, et les utiliser comme limites partagées.

Mais le logiciel, il mentionne - FME - a un transformateur appelé Generalizer qui les simplifier que vous le souhaitez tout en les conservant sous forme de polygones. L'option d'utiliser est appelée « Préserver les limites communes ». Vous pouvez télécharger FME [ici] [1] et demander une licence de eval 14 jours pour l'essayer.

est pas à proprement parler une réponse à votre question, mais si votre objectif ultime est de rendre des cartes dans le navigateur, alors vous devriez regarder dans le projet TopoJSON de Mike Bostock.

entrer image description ici

TopoJSON, comme GeoJSON, est un format de fichier javascript spatial convivial. Contrairement à GeoJSON, TopoJSON ne contient que la topologie de sorte que les frontières communes ne sont représentées qu'une seule fois. Il en résulte (a) des données plus compact et (b) la simplification transparente.

Il y a une excellente introduction ici, y compris en direct de visualisations l'algorithme utilisé pour déduire la topologie: http: / /bost.ocks.org/mike/topology/

Le wiki du projet est ici: https://github.com/mbostock/topojson

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