Hi List,

 

I'm looking for help with finding a way to create kernel density surfaces
with point count data.  The method needs to use the edge correction, so
initially I thought the methods in splancs would work.  But it looks like
kernel2d corrects for edge effects (it has an argument for a study area
polygon), but kernel3d does not appear to apply the edge correction.  Does
anyone know if there is a function that does 3D kernel density with edge
correction?  

 

Kernel3d has arguments for the following.  I would expect that xgr and ygr
would be equivalent to the points in the first points?  I think I'm probably
missing something here.  

     

      pts: A matrix of event coodinates x,y. 

 

   times: A vector of event times, t. 

 

     xgr: The values of x at which to compute the kernel function. 

 

     ygr: The values of y at which to compute the kernel function. 

 

     zgr: The values of time at which to compute the kernel function. 

 

     hxy: The quartic kernel width in the x and y direction. 

 

      hz: The quartic kernel width in the temporal direction. 

 

Any help or suggestions much appreciated,

 

Colin

 

Colin Robertson

MSc Candidate

Dept of Geography

University of Victoria

 

ph. (250)885-8065

 


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