[R] matching coordinates

[Don MacQueen]

If the pivoted portion and the previous section can be viewed as sets 
of line segments, there is a function in one of the spatial packages 
that tests for intersections between sets of line segments.

crossing.psp() in spatstat if I remember correctly.

-Don


At 10:26 AM -0800 11/19/06, sethlatimer wrote:
>I am trying to implement the so called pivot algorithm for a markov chain
>monte carlo simulation of self avoiding random walks.  There must be a
>simple method of checking to see if the pivoted portion of the random walk
>intersects with the previous section?
>
>In other words I have a list of adjacent coordinates divided into two parts.
>I apply an orthogonal transformation to one part and I need to check if it
>intersects with the other part before accepting the transformation. I am
>able to do it with a messy nest of loops but there must be a more elegant
>solution that I am missing.
>
>Thanks
>Seth Latimer
>--
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-- 
---------------------------------
Don MacQueen
Lawrence Livermore National Laboratory
Livermore, CA, USA