Hi folks,
After using spdep to construct a neighbor list from a SpatialPolygons
object, I plotted the neighbor list and noted that I needed one more link
that wasn't caught by the poly2nb command. I found the edit.nb() function
and can successfully use the interactive graphical interface to add th
Computing area on the spheroid:
Kimerling AJ. 1984. Area computation from geodetic coordinates on the
spheroid. Surveying and Mapping 44(4):343-351.
Measuring distortion:
Many cartography texts cover this. Analytical formulas for computing
distortion were developed by Tissot in the 19th century.
Ah, that is very useful. I'd always assumed the hard part is computing the
area of the triangles on the surface of a sphere/elipse, but perhaps that is
not so hard after all. Anyone have a reference to some simple formulas? The
other question is how much error is introduced if one computes areas af
Hi,
Is it possible to select all polygons that are (fully or partially)
within given geographical bounds? Either through some type of overlay or
by defining a box?
I have a feeling I have read about it somewhere, but I have not managed
to find it now when I needed it...
Morten
--
Morten Sick
