spCovAdd = function(observations, candidates, nDiff, nGridCells, plotOptim = TRUE, nTry,...){
# more arguments could be passed on function 'stratify' from package spcosa
net = SpatialPoints(observations)
nExist=length(coordinates(net)[,1])
nStrata = nExist+nDiff
newStrat = stratify( candidates, nStrata, net, nGridCells,
maxIterations = 1000, nTry = nTry, equalArea = F)
newPts = spsample(newStrat)
spData = as(newPts, "data.frame")
while(dim(spData)[1] < nExist+nDiff){
newStrat = stratify( candidates, nStrata, net, nGridCells,
maxIterations = 1000, nTry = nTry, equalArea = F)
newPts = spsample(newStrat)
spData = as(newPts, "data.frame")
}
names(spData)[1:2]=c("x","y")
if (class(candidates)[1] == "SpatialPolygonsDataFrame"){
if (plotOptim == TRUE){
plot(candidates)
add=data.frame(x=setdiff(as.data.frame(spData)$x, as.data.frame(net)$x),
y=setdiff(as.data.frame(spData)$y, as.data.frame(net)$y))
coordinates(add)=~x+y
points(add, pch=19, col="green")
points(net, pch=19, col=1, cex=0.7)
title('Spatial Coverage', xlab=paste("Adding", nDiff, "measurements"))
}
}
return(spData)
}
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.