Re: FindCurvePath has a problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg127422] Re: FindCurvePath has a problem*From*: Oliver Ruebenkoenig <ruebenko at wolfram.com>*Date*: Mon, 23 Jul 2012 19:55:52 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20120721034120.2CB6F68C2@smc.vnet.net>

On Fri, 20 Jul 2012, Oliver Ruebenkoenig wrote: > > > On Fri, 20 Jul 2012, Ralph Dratman wrote: > >> The following input to FindCurvePath produces the output shown below it: >> >> FindCurvePath[{{278,141},{279,141},{279,142},{279,143},{280,143},{280,144}, >> {280,145},{280,146},{281,147},{281,148},{281,149},{281,150},{282,150},{282, >> 151},{282,152},{283,151},{283,152},{283,153},{284,153},{284,154},{285,155}, >> {286,155},{286,156},{287,156},{287,157},{288,157},{289,156},{290,156},{290, >> 157},{291,156},{291,157},{292,156},{292,157},{293,156},{293,157},{294,156}, >> {294,157},{295,156},{295,157},{296,156},{296,157},{297,156},{297,157},{298, >> 155},{298,156},{299,155},{299,156},{300,155},{301,154},{301,155},{302,153}, >> {302,154},{303,152},{303,153},{304,150},{304,151},{304,152},{305,149},{305, >> 150},{306,146},{306,147},(*{306,148},{306,149},{307,144},{307,145},{307,146 >> },{308,141},{308,142},{308,143},{308,144},{309,139},{309,140},{309,141},{31 >> 0,138},{310,139},{311,136},{311,137},{311,138},{312,135},{312,136},{313,134 >> },{313,135},*){314,133},{314,134}}] >> FindCurvePath::ntri: The data generates an inconsistent >> triangulation. You can perturb the data to make it valid. >> >> Fail >> >> If you restore the commented-out list elements (beginning with >> (*{306,148}...), then evaluate, you get an apparently never-ending >> silent hangup, which is of course far worse than an error message. >> >> I have not yet tried to "perturb" anything to work around the problem. >> Clearly the function needs to check its arguments before wandering off >> into lala land. >> >> >> Ralph Dratman >> >> > > The only oddity is that it returns Fail in stead of $Failed, other than > that works on Linux-x86-64 V8.0.4. What version/OS do you have? > > Oliver > > Unfortunately, I must correct myself here, since I do see the hang as well. A copy and paste error made the data set work. Sorry about that. I filed this as a something too look at. This data set still works: FindCurvePath[{{278, 141}, {279, 141}, {279, 142}, {279, 143}, {280, 143}, {280, 144}, {280, 145}, {280, 146}, {281, 147}, {281, 148}, {281, 149}, {281, 150}, {282, 150}, {282, 151}, {282, 152}, {283, 151}, {283, 152}, {283, 153}, {284, 153}, {284, 154}, {285, 155}, {286, 155}, {286, 156}, {287, 156}, {287, 157}, {288, 157}, {289, 156}, {290, 156}, {290, 157}, {291, 156}, {291, 157}, {292, 156}, {292, 157}, {293, 156}, {293, 157}, {294, 156}, {294, 157}, {295, 156}, {295, 157}, {296, 156}, {296, 157}, {297, 156}, {297, 157}, {298, 155}, {298, 156}, {299, 155}, {299, 156}, {300, 155}, {301, 154}, {301, 155}, {302, 153}, {302, 154}, {303, 152} , {303, 153}, {304, 150}, {304, 151}, {304, 152}, {305, 149}, {305, 150}, {306, 146}, {306, 147}, {306, 148}, {306, 149}, {307, 144}, {307, 145} , {307, 146}, {308, 141}, {308, 142}, {308, 143}, {308, 144}, {309, 139} , {309, 140}, {309, 141}, {310, 138}, {310, 139}, {311, 136}, {311, 137} , {311, 138}, {312, 135}, {312, 136}, {313, 134} , {313, 135} (*,{314,133},{314,134}*)}] Oliver

**References**:**Re: FindCurvePath has a problem***From:*Oliver Ruebenkoenig <ruebenko@wolfram.com>