Hallo Birgit, your Multilinestring can not be convert to a valid linestring. ST_Linemerge give not a Linestring. The parts 2 and 3 have the same start and endpoint
Gr Ralf Am Montag 17 Januar 2011, 15:51:49 schrieb Birgit Laggner: > Dear list, > > perhaps somebody could clear things for me: > > If I run the query below, the result is "false". But I don't understand > why. I always thought, as long as there exists a continuous chain of > start and end points, a MultiLineString would be closed. Am I wrong > somehow? > > Thanks and regards, > > Birgit. > > > select st_isclosed(st_geomfromtext( > 'MULTILINESTRING( > (3584442.63274253 5842172.41579578, > 3584358.9809 5842152.7361, > 3584355.23337321 5842153.70245931), > (3584355.23337321 5842153.70245931, > 3584355.23330909 5842153.70247585, > 3584355.23339452 5842153.70245382, > 3584355.23337321 5842153.70245931), > (3584355.23337321 5842153.70245931, > 3584348.03488658 5842155.55873215, > 3584345.68905341 5842155.07665686, > 3584343.82931858 5842154.69447615, > 3584340.46724669 5842152.9072508, > 3584338.14023057 5842151.67024508, > 3584328.33210257 5842146.45639614, > 3584009.05607027 5842072.59988407, > 3583887.98803815 5842042.75796404, > 3583790.05011806 5842106.6478841, > 3583790.05012 5842106.64788453, > 3583878.43617231 5842126.47539268, > 3584324.73120656 5842226.59207621, > 3584329.67415529 5842229.44269127, > 3584334.41005457 5842232.17390022, > 3584368.1119426 5842240.76423623, > 3584463.63629469 5842262.81966025, > 3584488.97911407 5842268.84731974), > (3584488.97911407 5842268.84731974, > 3584488.97978147 5842268.84747848, > 3584488.97978146 5842268.84747848, > 3584488.97911407 5842268.84731974), > (3584488.97911407 5842268.84731974, > 3584488.97890809 5842268.84727075, > 3584464.1099 5842262.3082, > 3584464.10990818 5842262.30817579, > 3584466.07027273 5842256.50678355, > 3584472.08934014 5842238.694295, > 3584472.08940751 5842238.69409565, > 3584489.545 5842187.037, > 3584489.5450305 5842187.03700481, > 3584489.54503071 5842187.03700417, > 3584526.86014482 5842192.92533864, > 3584514.30279074 5842190.12385218, > 3584495.65165472 5842186.30586817, > 3584480.67207071 5842180.87201217, > 3584458.64642469 5842176.18313362, > 3584458.64634269 5842176.18311617, > 3584442.63469631 5842172.41625542, > 3584442.63274253 5842172.41579578))',31467)); > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
