>There are several algorithms mentioned on that page. Do you need the > diameter, width, or something else?
Oh , I did not realize that .Actually first i implemented diameter algorithm [ http://hpaste.org/49925 ] and tested it on couple of test cases . Its working fine then i tried to implement " The minimum area enclosing rectangle for a convex polygon" using four calipers but i don't know whats wrong code. > Do you have some example data and what wrong result you get? For any test input [ which i tried ] it outputs 4 . If its implemented correctly then it will accepted here with slight modification [ http://www.spoj.pl/problems/WLOO0707 ] since it asks for square area. Couple of test cases which i tried . ghci>final [ P 1 1 , P 2 2 , P 0 100 , P 0 1 ] Loading package array-0.3.0.0 ... linking ... done. Loading package bytestring-0.9.1.5 ... linking ... done. 4.0 ghci>final [ P 0 0 ,P 5 1 , P 9 2 , P 12 3 , P 14 4 , P 15 5 , P 16 7 , P 17 10 , P 18 14 , P 19 19 ] 3.9999999999999982 ghci>final [ P 2 ( -3 ) , P (-1 ) 2 , P 0 5 , P (-5) (-1) , P (-4) ( 2 ) , P 4 0 , P 1 3 , P 4 3 , P (-3) (-4) , P 0 (-2)] 4.0 Thank you Mukesh Tiwari On Aug 6, 10:32 pm, Tillmann Vogt <tillmann.v...@rwth-aachen.de> wrote: > Am 06.08.2011 13:12, schrieb mukesh tiwari:> Hello all , > Hi > > I am trying to understand rotating calipers [ > >http://en.wikipedia.org/wiki/Rotating_calipers] but i am not sure if > > understood this algorithm correctly . I tried to use the almost same > > algorithm given on wiki but with four calipers to solve the problem > > [http://cgm.cs.mcgill.ca/~orm/rotcal.html]. > > There are several algorithms mentioned on that page. Do you need the > diameter, width, or something else? > > > My approach is find > > xminP, xmaxP, yminP ymaxP and their corresponding calipers will be ( 0 > > * i - j ) , ( o * i + j ) , ( i + 0 * j ) and ( -i + 0 * j ). I > > implemented the algorithm in Haskell but its not working . I am not > > sure if i have followed the wiki algorithm correctly and could some > > one please tell me what is wrong with implementation. It would be > > great if some one can explain this algorithm in pseudo code which > > explains the rotating caliper and their implementation details . In > > case of indentation , see here [http://hpaste.org/49907] . > > Thank you > > Mukesh Tiwari > > I tried your code on one of my libraries. The convex hull function seems > to works correctly (I could send you a screenshot). I hope this narrows > the search down. Do you have some example data and what wrong result you > get? > > In one of my libraries > (http://hackage.haskell.org/packages/archive/collada-types/0.3/doc/htm...) > there is a function: > > streamAnimation :: [(Float,Float,Float)] -> [SceneNode] -> [Animation] > > that can visualize a stream of points by an animation. I use this > sometimes for debugging. > > -Tillmann > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-C...@haskell.orghttp://www.haskell.org/mailman/listinfo/haskell-cafe _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe