[postgis-users] Problem : Within() incorrectly returns 'false'

Arnaud Lesauvage thewild at freesurf.fr
Mon Jan 8 01:44:17 PST 2007 

Hi List !

I have a problem with the Within() function.
I use it to test whether points are within polygons, in conjunction with '&&' 
for index use.
In some cases, Within() returns false even though the point is obviously within 
the polygon.
Here is an example of such a behaviour (note that I test the polygon for 
validity, and IsValid returns 'true') :

mydb=# select postgis_full_version();
                                           postgis_full_version
--------------------------------------------------------------------------------------------------------
  POSTGIS="1.2.0" GEOS="2.2.3-CAPI-1.1.1" PROJ="Rel. 4.5.0, 22 Oct 2006" 
USE_STATS (procs 1.1.0 upgrade)
(1 row)

mydb=# SELECT GeomFromText('POINT(455663 4973705)',32631) && 
GeomFromText('POLYGON((455634.327007261 4973739.18140708,455640.390824553 
4973742.34545851,455649.974963534 4973744.72838799,455655.302230411 
4973744.81018619,455666.871609771 4973741.51734043,455673.066844244 
4973737.99160574,455682.857256671 4973731.31013028,455696.77629443 
4973721.97329467,455713.453957339 4973712.16884477,455721.42334697 
4973707.86016838,455737.50239802 4973705.84732456,455748.289255495 
4973707.80971155,455768.964516862 4973713.10563678,455789.467434074 
4973718.30527948,455809.877573217 4973718.59365931,455816.032949075 
4973711.16573985,455819.835126931 4973702.44653788,455824.05944495 
4973691.47543162,455824.05944495 4973691.47543162,455828.610407021 
4973680.12283995,455830.970634323 4973674.90248145,455833.367228335 
4973670.30554483,455838.223766503 4973663.87857158,455853.056176824 
4973662.3695754,455866.6601998 4973666.33738459,455872.247284383 
4973667.83016243,455891.21742699 4973672.66515592,455904.87965274 
4973676.20206359,455925.323306466 4973681.93577574,455931.93236638 
4973683.83511874,455963.188375863 4973690.90230387,455986.900652308 
4973690.57770489,455999.308881106 4973688.08608035,456
006.847072463 4973685.91128035,456013.781894891 4973682.68047389,456020.04917607 
4973677.53977996,456028.058802994 4973664.42994524,456032.395247822 
4973652.08166202,456034.250253643 4973645.32660031,456037.315382866 
4973631.6242598,456038.518126576 4973625.06483024,456039.49606989 
4973618.95846064,456041.143946469 4973604.12669801,456041.322480722 
4973600.16812515,456041.234269879 4973593.33220285,456040.255579245 
4973584.79199929,456038.077220394 4973576.88018093,456031.407673379 
4973564.92278014,456022.584091079 4973553.60498374,456015.530632601 
4973545.35673604,456011.870844281 4973541.1846865,456001.221309389 
4973529.12192161,455991.929965679 4973518.46446974,455982.111242839 
4973507.13762537,455975.429739526 4973499.25369943,455968.699421007 
4973481.2156405,455968.569127113 4973472.22440673,455968.681690362 
4973469.48222644,455968.364280116 4973459.20668792,455964.198441514 
4973452.80965392,455957.352768727 4973451.16429375,455950.970005851 
4973451.05854393,455925.042572423 4973453.79303565,455920.580033511 
4973454.95190268,455916.338152812 4973456.411639,455908.870067239 
4973460.36365329,455899.377173016 4973468.20421239,455892.64054911 
4973473.70250239,455884.308266302 4973
478.59803378,455873.700962084 4973482.45761784,455861.855176683 
4973485.90236361,455859.696574931 4973492.55059044,455844.389439454 
4973492.39432963,455839.411700775 4973495.34512154,455831.33685203 
4973502.9194365,455825.191393046 4973512.52991105,455822.579473065 
4973518.00029755,455817.751828832 4973530.0745478,455812.814767254 
4973543.24550764,455807.105870701 4973557.06881857,455803.959640509 
4973563.64623146,455796.916583005 4973575.41517021,455792.972660989 
4973580.26754987,455786.234602819 4973585.77560012,455773.906298319 
4973590.19110681,455755.880529301 4973589.95244674,455741.983929337 
4973588.07856712,455734.473975748 4973587.00298353,455726.703007087 
4973585.92187192,455710.902303958 4973583.8726695,455695.630378757 
4973582.19016965,455688.520382506 4973581.56743626,455675.978583625 
4973580.92133312,455661.611205371 4973581.95574872,455651.587526438 
4973586.21821552,455646.738207892 4973591.31382874,455642.936132872 
4973598.59694555,455639.807137755 4973608.4661572,455638.377942947 
4973614.49593153,455636.97649546 4973621.32268911,455634.084325749 
4973637.51733042,455631.585960851 4973653.17474669,455630.344123986 
4973661.50140289,455629.696234567 4973665.93866226,455
629.696234567 4973665.93866226,455628.383269606 4973675.5239203,455626.235378731 
4973693.34686891,455624.997527166 4973707.75141773,455625.052806357 
4973722.19487999,455626.239816571 4973728.34327406,455630.963831745 
4973736.33081102,455634.327007261 4973739.18140708))',32631),
mydb-# Within(GeomFromText('POINT(455663 4973705)',32631), 
GeomFromText('POLYGON((455634.327007261 4973739.18140708,455640.390824553 
4973742.34545851,455649.974963534 4973744.72838799,455655.302230411 
4973744.81018619,455666.871609771 4973741.51734043,455673.066844244 
4973737.99160574,455682.857256671 4973731.31013028,455696.77629443 
4973721.97329467,455713.453957339 4973712.16884477,455721.42334697 
4973707.86016838,455737.50239802 4973705.84732456,455748.289255495 
4973707.80971155,455768.964516862 4973713.10563678,455789.467434074 
4973718.30527948,455809.877573217 4973718.59365931,455816.032949075 
4973711.16573985,455819.835126931 4973702.44653788,455824.05944495 
4973691.47543162,455824.05944495 4973691.47543162,455828.610407021 
4973680.12283995,455830.970634323 4973674.90248145,455833.367228335 
4973670.30554483,455838.223766503 4973663.87857158,455853.056176824 
4973662.3695754,455866.6601998 4973666.33738459,455872.247284383 
4973667.83016243,455891.21742699 4973672.66515592,455904.87965274 
4973676.20206359,455925.323306466 4973681.93577574,455931.93236638 
4973683.83511874,455963.188375863 4973690.90230387,455986.900652308 
4973690.57770489,455999.308881106 4973688.08608035,45600
6.847072463 4973685.91128035,456013.781894891 4973682.68047389,456020.04917607 
4973677.53977996,456028.058802994 4973664.42994524,456032.395247822 
4973652.08166202,456034.250253643 4973645.32660031,456037.315382866 
4973631.6242598,456038.518126576 4973625.06483024,456039.49606989 
4973618.95846064,456041.143946469 4973604.12669801,456041.322480722 
4973600.16812515,456041.234269879 4973593.33220285,456040.255579245 
4973584.79199929,456038.077220394 4973576.88018093,456031.407673379 
4973564.92278014,456022.584091079 4973553.60498374,456015.530632601 
4973545.35673604,456011.870844281 4973541.1846865,456001.221309389 
4973529.12192161,455991.929965679 4973518.46446974,455982.111242839 
4973507.13762537,455975.429739526 4973499.25369943,455968.699421007 
4973481.2156405,455968.569127113 4973472.22440673,455968.681690362 
4973469.48222644,455968.364280116 4973459.20668792,455964.198441514 
4973452.80965392,455957.352768727 4973451.16429375,455950.970005851 
4973451.05854393,455925.042572423 4973453.79303565,455920.580033511 
4973454.95190268,455916.338152812 4973456.411639,455908.870067239 
4973460.36365329,455899.377173016 4973468.20421239,455892.64054911 
4973473.70250239,455884.308266302 497347
8.59803378,455873.700962084 4973482.45761784,455861.855176683 
4973485.90236361,455859.696574931 4973492.55059044,455844.389439454 
4973492.39432963,455839.411700775 4973495.34512154,455831.33685203 
4973502.9194365,455825.191393046 4973512.52991105,455822.579473065 
4973518.00029755,455817.751828832 4973530.0745478,455812.814767254 
4973543.24550764,455807.105870701 4973557.06881857,455803.959640509 
4973563.64623146,455796.916583005 4973575.41517021,455792.972660989 
4973580.26754987,455786.234602819 4973585.77560012,455773.906298319 
4973590.19110681,455755.880529301 4973589.95244674,455741.983929337 
4973588.07856712,455734.473975748 4973587.00298353,455726.703007087 
4973585.92187192,455710.902303958 4973583.8726695,455695.630378757 
4973582.19016965,455688.520382506 4973581.56743626,455675.978583625 
4973580.92133312,455661.611205371 4973581.95574872,455651.587526438 
4973586.21821552,455646.738207892 4973591.31382874,455642.936132872 
4973598.59694555,455639.807137755 4973608.4661572,455638.377942947 
4973614.49593153,455636.97649546 4973621.32268911,455634.084325749 
4973637.51733042,455631.585960851 4973653.17474669,455630.344123986 
4973661.50140289,455629.696234567 4973665.93866226,45562
9.696234567 4973665.93866226,455628.383269606 4973675.5239203,455626.235378731 
4973693.34686891,455624.997527166 4973707.75141773,455625.052806357 
4973722.19487999,455626.239816571 4973728.34327406,455630.963831745 
4973736.33081102,455634.327007261 4973739.18140708))',32631));
  ?column? | within
----------+--------
  t        | f
(1 row)



Does anyone know what's wrong with my PostIS ?

Thanks !
--
Arnaud

More information about the postgis-users mailing list