| hexGrid {spBayes} | R Documentation |
This function generates a hexagon tessellation within a bounding box.
hexGrid(nodes.per.layer, b.box, ...)
nodes.per.layer |
the number of hexagons from min.x to max.x at min.y. |
b.box |
the domain's bounding box defined with a vector of length
four and elements ordered min.x, min.y, max.x, max.y. |
... |
currently no additional arguments. |
A list with the following tags:
hx.hy |
a vector of length two that holds the height and width, respectively, between hexagon centroids. |
layers |
the number of hexagon layers within the domain. |
nodes.per.layer |
the number of hexagons from min.x to max.x at min.y. |
hex.centroids |
an nx2 matrix with rows corresponding the the x and y coordinates of the n hexagons within the domain. |
hex.polygons |
a list with 6x2 matrices which hold the hexagons' x and y vertices coordinates. |
Andrew O. Finley finleya@msu.edu,
Sudipto Banerjee baner009@umn.edu
## Not run:
##Define the bounding box and make the call
b.box <- c(0,0,10,10)
out <- hexGrid(20, b.box)
##Plot using lapply
par(mfrow=c(1,2))
plot(out$hex.centroids, pch=19, cex=0.5,
ylab="Northing", xlab="Easting")
lapply(out$hex.polygons, polygon, col="blue")
##Now color hexagons based on value
my.col.ramp <- function(z){
zlim <- range(z)
zlen <- zlim[2]-zlim[1]+1
colorlut <- heat.colors(as.integer(zlen))
col <- colorlut[z-zlim[1]+1]
col
}
n <- nrow(out$hex.centroids)
col <- my.col.ramp(rnorm(n))
plot(out$hex.centroids, typ="n", ylab="", xlab="Easting")
for(i in 1:n){
polygon(out$hex.polygons[[i]], col=col[i], border=col[i])
}
## End(Not run)