Hi. sorry for the late reply, I only came back from abroad. The best thing to do, would be to try the WKT of the geometry on the jts testbuilder [0] and see if the result is the same.
It might be a problem of precision model. Cheers, Andrea [0] http://sourceforge.net/projects/jts-topo-suite/ On Mon, Feb 4, 2013 at 1:45 PM, suryakant bhagat <[email protected]>wrote: > Hi Andrea, > Has the replication after zooming out given any clue? I guess > the issue lies in the difference method. What do you think? > > > Suryakant B > > > > --- On *Thu, 31/1/13, suryakant bhagat <[email protected]>* wrote: > > > From: suryakant bhagat <[email protected]> > > Subject: Re: [udig-devel] Fill Area tool does not give correct results > always > To: "User-friendly Desktop Internet GIS" <[email protected] > > > Date: Thursday, 31 January, 2013, 4:08 PM > > > Hi Andrea, > I replicated the same issue after zooming. I got following > results: > 1. Created Geometry :POLYGON ((-136.36207894120835 70.82320538055232, > -136.36208094140173 70.82320527169826, -136.36207926777053 > 70.82320298576306, -136.36207793430827 70.82320284969549, > -136.36207683216088 70.82320442807932, -136.36207894120835 > 70.82320538055232)) > > 2. Existing Geometry :MULTIPOLYGON (((-136.36207691384476 > 70.82320209866847, -136.3620769138448 70.82320209866847, -136.3620768593744 > 70.82320055015353, -136.36208075090713 70.82320084950219, > -136.3620800569625 70.82320378856173, -136.3620789548151 70.8232048498888, > -136.36207917475403 70.82320463809577, -136.3620794718719 > 70.82320604728342, -136.36207832890423 70.82320574793476, -136.362078166789 > 70.82320559683706, -136.36207570279998 70.82320546219286, > -136.36207260045921 70.82320260477387, -136.36207526738374 > 70.82320037326569, -136.36207690696492 70.82320190308404, > -136.36207691384476 70.82320209866847)), ((-137.52380967661375 > 69.71428579174602, -160.00000017777776 67.80952388486772, > -162.28571446603172 87.61904771640211, -145.52380968550264 > 90.6666667674074, -129.1428572863492 77.71428580063491, -137.52380967661375 > 69.71428579174602))) > > 3. Difference Geometry :POLYGON ((-136.36207993882437 70.82320390232437, > -136.36208094140173 70.82320527169826, -136.3620793268708 > 70.82320535956389, -136.36207917475403 70.82320463809577, > -136.3620789548151 70.8232048498888, -136.36207993882437 70.82320390232437)) > > I have also attached the image which shows the erroneous extra line > attached to the polygon(highlighted in the image). > > Suryakant B > > --- On *Thu, 31/1/13, andrea antonello <[email protected]>*wrote: > > > From: andrea antonello <[email protected]> > Subject: Re: [udig-devel] Fill Area tool does not give correct results > always > To: "User-friendly Desktop Internet GIS" <[email protected] > > > Date: Thursday, 31 January, 2013, 12:51 PM > > > Thanks for replying back. As suggested by you, I can try the > same in a reprojected system. But, which coordinate system should I > use(there are may u know)? I had reported the issue using the coordinate > system GEOG/WGS 84. > > > Well, you could try any UTM of your zone, for which you have data. > Another test would be to zoom at a major level of detail, i.e. still in > lat/long but at a higher zoom in. Can for exampke zoom to the level of > detail of your house and try there? > > Cheers, > Andrea > > > > > > > Suryakant B > > --- On *Wed, 30/1/13, andrea antonello <[email protected]>*wrote: > > > From: andrea antonello <[email protected]> > Subject: Re: [udig-devel] Fill Area tool does not give correct results > always > To: "User-friendly Desktop Internet GIS" <[email protected] > > > Date: Wednesday, 30 January, 2013, 11:39 AM > > > Hi Suryakant, > that is quite one interesting issue. > > I am wondering if that is a problem of precision model. In your case you > are using very wide lat long coordinates, which might lead at that level of > non-detail to some rounding issues in the JTS results? > Can you try the same in a reprojected system? > > I tried to check the geometries you report in the JTS testbuilder and they > already have the extra lines. > > Let me know how the tests go, I will check also as soon as I can. > > Andrea > > > > > > On Wed, Jan 30, 2013 at 6:08 AM, suryakant bhagat > <[email protected]<http://mc/[email protected]> > > wrote: > > Hi, > I am using 2 tools as follows. > 1. Create Polygon Tool ==> I draw a polygon. I have numbered it as 1 in > the attached image. > 2. Fill Area Tool ==> I use the fill tool and complete filling area marked > 2 in the attached image. I again use the fill tool and complete filling > area marked 3 in the attached image. > Now the resultant polygon marked 3 is incorrectly filled. The > resultant polygon has an extra line(highlighted in the image) which should > not be present in the resultant polygon. > I did a walkthrough of the code to understand the cause. I debugged the > method > runDifferenceOp in the class DifferenceFeatureCommand. After I complete > filling area marked 3 in the attached image, I get following results. > 1. The createdGeometry is POLYGON ((-67.39088271309409 27.934044647914646, > -74.37439387507274 60.75654710921435, -55.16973817963144 83.10378282754607, > -16.062075672550947 67.39088271309407, -13.967022323957337 > 37.36178471658584, -24.791464625024247 9.427740068671199, > -67.39088271309409 27.934044647914646)) > > 2. The existingGeometry is POLYGON ((-47.951394159917214 > 44.09570912400787, -53.07468483103783 53.77303594723569, > -12.221144533462677 57.61396708632395, 27.584869089815697 > 29.33074688031038, 15.0145489982541 -14.316197882056258, -9.15177506194378 > 3.405773095422192, 0.3491755580989206 3.840931139088269, > -45.392822552861304 1.7458777904946743, -82.40543171134821 > 5.237633371483994, -85.19883617613966 43.64694476236663, > -27.235693531716777 44.3452958785645, -47.951394159917214 > 44.09570912400787)) > > 3. The differenceGeometry is POLYGON ((-70.77103782166621 > 43.82077365820366, -74.37439387507274 60.75654710921435, -55.16973817963144 > 83.10378282754607, -16.062075672550947 67.39088271309407, > -15.359380547632652 57.3189192559319, -53.07468483103783 53.77303594723569, > -47.951394159917214 44.09570912400787, -27.235693531716777 > 44.3452958785645, -70.77103782166621 43.82077365820366)) > > The difference calculated is incorrect. It is not as per the definition of > the method given in the api. I am quoting the api definition here(* > com.vividsolutions.jts.geom.Geometry*). > > -------------------------------------------------------------------------------------------------------------------------------- > difference > > public Geometry > <http://in.mc1903.mail.yahoo.com/com/vividsolutions/jts/geom/Geometry.html> > *difference*(Geometry > <http://in.mc1903.mail.yahoo.com/com/vividsolutions/jts/geom/Geometry.html> > other) > > Computes a Geometry representing the points making up this Geometry that > do not make up other. This method returns the closure of the resultant > Geometry. > *Parameters:* other - the Geometry with which to compute the difference > *Returns:* the point set difference of this Geometry with other > > ----------------------------------------------------------------------------------------------------------------------------------- > Is it a bug or I am wrong in my undersatnding. Also, how do I correct it? > Please let me know. > > > Thanks and Regards, > Suryakant B > > _______________________________________________ > User-friendly Desktop Internet GIS (uDig) > http://udig.refractions.net > http://lists.refractions.net/mailman/listinfo/udig-devel > > > > -----Inline Attachment Follows----- > > > _______________________________________________ > User-friendly Desktop Internet GIS (uDig) > http://udig.refractions.net > http://lists.refractions.net/mailman/listinfo/udig-devel > > > _______________________________________________ > User-friendly Desktop Internet GIS (uDig) > http://udig.refractions.net > http://lists.refractions.net/mailman/listinfo/udig-devel > > > > -----Inline Attachment Follows----- > > _______________________________________________ > User-friendly Desktop Internet GIS (uDig) > http://udig.refractions.net > http://lists.refractions.net/mailman/listinfo/udig-devel > > > -----Inline Attachment Follows----- > > _______________________________________________ > User-friendly Desktop Internet GIS (uDig) > http://udig.refractions.net > http://lists.refractions.net/mailman/listinfo/udig-devel > > > _______________________________________________ > User-friendly Desktop Internet GIS (uDig) > http://udig.refractions.net > http://lists.refractions.net/mailman/listinfo/udig-devel > >
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