Area of closed polygon.
Returns area of polygon.
jarea(L)
L
If polygon is counter clockwise (CCW) area will be positive, else negative. If not sure, take absolute value of output.
Area in dimensions of x,y
Jonathan M. Leesjonathan.lees@unc.edu
set.seed(12) X = runif(10, 1, 100) Y = runif(10, 1, 100) hc = chull(X, Y) #### looks like chull returns points in clockwise L = list(x=X[hc] , y=Y[hc] ) j1 = jarea(L ) ######### reverse order of polygon jc = rev(hc) L = list(x=X[jc] , y=Y[jc] ) j2 = jarea(L )
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