[R-sig-Geo] Creating polygons out of an irregular data set to represent specific classes
v8extra at gmail.com
Fri Dec 3 02:08:44 CET 2010
Hello to all,
I have struggling with R for at least a weak and I guess I do really need your help figuring this out.
I have to work with a large data set (thousands of points) and to create figures that are small and good looking for publications.
You can probably suggest me a slick a working way to approach this problem.
I would really appreciate.
Let say we start with:
ak.li=interp(akima$x, akima$y, akima$z, xo=seq(min(akima$x), max(akima$x), length = dimgrid),yo=seq(min(akima$y), max(akima$y), length = dimgrid),linear = TRUE, extrap=FALSE, duplicate = "mean")
# Now I have the regular grid.
cLines = contourLines(x = ak.li$x, y = ak.li$y, z = ak.li$z, nlevels = 7)
# Now I have the contours...
That is from that point on that I cannot find a solution.
I tough of selecting all the image data and converting it a specific class value, but then I still get stuck into the same issue I dont know how to convert those pixel into polygons.
I do need guidance...
Thanks a lot!
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