| gc2gpc {AIGIS} | R Documentation |
Given a vector indicating minimum and maximum latitude and longitudes, creates a rectangular polygon of class gpc.poly, which can then be used by other areal weighting functions. This is simply a very thin wrapper for as(...,\dQuote{gpc.poly}, and use primarily as a convenient internal function.
gc2gpc(bounds)
bounds |
A vector of length four, who's entries are (in order): Minimum longitude, maximum longitude, minimum latitude, maximum latitude. |
A rectangular polygon object of class gpc.poly.
Benjamin P. Bryant, bryant@prgs.edu
poly1 <- gc2gpc(c(0,1,0,1))
poly2 <- gc2gpc(c(.3,1.1,.25,1.02))
plot(poly1)
plot(poly2,add=TRUE)
plot(intersect(poly1,poly2), poly.args=list(col="blue"),add=TRUE)
## The function is currently defined as
function(bounds){
minglon <- bounds[1]
maxglon <- bounds[2]
minglat <- bounds[3]
maxglat <- bounds[4]
gpoly <- cbind(c(minglon, maxglon, maxglon, minglon),c(minglat,
minglat, maxglat, maxglat))
gpoly <- as(gpoly, "gpc.poly")
return(gpoly)
}