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)