[R-sig-Geo] Polygon perimeter calculation in PBSmapping?

[Takatsugu Kobayashi]

Hi,

I created a grid of cells of varying sizes using makeGrid() in sp. I 
could calculated the areas of these cells of varying sizes using 
calcArea() and combinePolys() in PBSmapping. I wonder if there is a 
function with which to compute the perimeter length. Or should I convert 
polygons to polylines and use calcLengths()?

Thank you very much.

Taka