gxgy.to.hectindex {CTFS} | R Documentation |
This function takes an x, y plot location and identifies the hectare
number. The far edges of the plot is considered out-of-bounds. The
same results can be obtained by using a gridsize of 100 by 100 with
the function gxgy.to.index
.
gxgy.to.hectindex(gx, gy, plotdim = c(1000, 500))
gx |
tree x coordinate |
gy |
tree y coordinate |
plotdim |
dimensions of the plot: east-west 1000m and north-south 500m |
The function should work for any 4 sided plot, square or rectangular. The convention is to number the hectares starting in the southwest corner and going northward up a "column" of 5, and returning to the southern border for 6-10, etc.
Returns a vector, the hectare number (default values range from 1 to 50). Returns a -1 when an invalid gx or gy value is given.
Rick Condit, Suzanne Lao and Pamela Hall
## Not run: tst.gy=c(0,499,0,499) tst.gx=c(0,0,999,999) gxgy.to.hectindex(tst.gx,tst.gy) # the same values can be obtained using gxgy.to.index with a gridsize of 100 gxgy.to.hectindex(783,456) gxgy.to.index(783,456,gridsize=100) ## End(Not run)