[GRASS-dev] Re: [GRASS GIS] #331: extend the vector modell to be able to calculate real circular segments and circles => for calculating real circular buffers of points

[GRASS GIS]

#331: extend the vector modell to be able to calculate real circular segments and
circles => for calculating real circular buffers of points
--------------------------+-------------------------------------------------
  Reporter:  mlechner     |       Owner:  grass-dev at lists.osgeo.org       
      Type:  enhancement  |      Status:  new                             
  Priority:  minor        |   Milestone:  7.0.0                           
 Component:  Vector       |     Version:  svn-trunk                       
Resolution:               |    Keywords:  vector model curve circle buffer
  Platform:  All          |         Cpu:  All                             
--------------------------+-------------------------------------------------
Changes (by hamish):

  * priority:  major => minor
  * platform:  Unspecified => All
  * version:  unspecified => svn-trunk
  * component:  default => Vector
  * cpu:  Unspecified => All

Comment:

 Replying to [ticket:331 mlechner]:
 > It would be interesting to extend the grass vector model to be
 > able to construct curves for using them to create real circular
 > buffers instead of approximating them using several vertices.
 >
 > I just was wondering - isn't it more effectice saving a buffer
 > using one vertice and a "curved line" than using several points
 > and approximate the circle.
 >
 > An appproximated buffer could still be in the data - only newly
 > calculated buffers are more correct then.


 Hi,

 I remember some years ago seeing a presentation about a similar idea. The
 talk was entitled “The circle tree – a hierarchical structure for
 efficient storage, access and multi-scale representation of spatial data”,
 by Antoni Moore.

 http://www.business.otago.ac.nz/SIRC/conferences/2002_SIRC/17_Moore.pdf
 (and also another talk at SIRC 2003)


 Tony's office is just down the hall, if needed I can ask him where it
 lead. ISTR they had a prototype and did some efficacy testing.
 (or you can just use that as scholar.google search terms for
 publications...)


 perhaps this wish is "easier said than done".

 see also the symbol library, which has a hybrid cartesian/polar polyline
 input method.



 Hamish

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Ticket URL: <http://trac.osgeo.org/grass/ticket/331#comment:1>
GRASS GIS <http://grass.osgeo.org>