spaMM (version 1.4.1)

seaMask: Masks of seas or lands

Description

These convenient masks can be added to maps of (parts of) the world to mask map information for these areas.

Usage

data(seaMask)
data(landMask)

format

seaMask and landMask are data frames with two variables, x and y for longitude and latitude. Its contents are suitable for use with polypath: they define different polygones, each separated by a row of NAs.

Details

polypath requires polygons, while map(interior=FALSE,plot=FALSE) returns small segments. landMask is the result of reconnecting the segments into full coastlines of all land blocks.

Examples

data(seaMask)
## plot of predictions of behaviour for a land bird:
if (require(maps)){
 data(blackcap)
 bfit <- corrHLfit(migStatus ~ means+ Matern(1|longitude+latitude),data=blackcap,
                  HLmethod="ML",
                  ranFix=list(lambda=0.5537,phi=1.376e-05,rho=0.0544740,nu=0.6286311))
 ## We add small masks to the points on small islands to see the predictions there
 ll <- blackcap[,c("longitude","latitude")]
 pointmask <- function(xy,r=1,npts=12) {
  theta <- 2*pi/npts *seq(npts)
  hexas <- lapply(seq(nrow(xy)),function(li){
    p <- as.numeric(xy[li,])
    hexa <- cbind(x=p[1]+r*cos(theta),y=p[2]+r*sin(theta))
    rbind(rep(NA,2),hexa) ## inital NA before each polygon
  })
  do.call(rbind,hexas)
 }
 pmasks <- pointmask(ll[c(2,4,5,6,7),],r=0.8) ## small islands only
 filled.mapMM(bfit,add.map=TRUE,
             plot.title=title(main="Inferred migration propensity of blackcaps",
                               xlab="longitude",ylab="latitude"),
             add.points=quote(points(pred[,coordinates],cex=1,pch="+")),
             plot.axes={axis(1);axis(2);
                        polypath(rbind(seaMask,pmasks),border=FALSE,
                                 col="grey", rule="evenodd")
             })
}