how to derive true surface area from `computeContour3d' (misc3d package) -- follow up
On Fri, 08 Nov 2013 15:32:00 +0100, Barry Rowlingson
<b.rowlingson at lancaster.ac.uk> wrote:
On Fri, Nov 8, 2013 at 1:01 PM, j. van den hoff <veedeehjay at googlemail.com> wrote:
ps: it of course would still be nice, if the surface area (or a vector containing the individual triangle areas) were returned to the caller as well ...
Does the 'surfaceArea' function in the sp package do what you want? It's Edzer's integration of an R function that I wrote that calls some C code that someone else wrote that implements an algorithm from 2004. You just need to coerce your grid data into the right form.
not quite, I believe: I need to compute the area of a (closed) iso-surface of a 3D object defined by samples on a discrete 3D grid. if I understand correctly from a quick view on `sp', `surfaceArea' does compute the surface integral of some function z = f(x,y), instead. but thanks for the pointer anyway, this might still be useful in a different context. joerg
Barry
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