| northernFurSeal {crawl} | R Documentation |
Northern fur seal pup relocation data set used in Johnson et al. (2008)
data(northernFurSeal)
A data frame with 795 observations on the following 4 variables:
TimeArgos_loc_class0 1
2 3 A.latitudelongitude
Alska Ecosystems Program National Marine Mammal Laboratory Alaska Fisheries Science Center National Marine Fisheries Service, NOAA 7600 Sand Point Way NE Seattle, WA 98115
Johnson, D., J. London, M. -A. Lea, and J. Durban (2008) Continuous-time random walk model for animal telemetry data. Ecology 89:1208-1215.
data(northernFurSeal)
argosClasses <- c("3", "2", "1", "0", "A", "B")
ArgosMultFactors <- data.frame(Argos_loc_class=argosClasses,
errX=log(c(1, 1.5, 4, 14, 5.21, 20.78)),
errY=log(c(1, 1.5, 4, 14, 11.08, 31.03)))
nfsNew <- merge(northernFurSeal, ArgosMultFactors,
by=c("Argos_loc_class"), all.x=TRUE)
nfsNew <- nfsNew[order(nfsNew$Time), ]
# State starting values
initial.drift <- list(a1.x=c(189.686, 0, 0), a1.y=c(57.145, 0, 0),
P1.x=diag(c(0, 0.001, 0.001)),
P1.y=diag(c(0, 0.001, 0.001)))
##Fit random drift model
fit <- crwMLE(mov.model=~1, err.model=list(x=~errX, y=~errY), drift.model=TRUE,
data=nfsNew, coord=c("longitude", "latitude"),
Time.name="Time", initial.state=initial.drift, polar.coord=TRUE,
fixPar=c(NA, 1, NA, 1, NA, NA, NA,NA),
control=list(maxit=2000,trace=1, REPORT=10))
##Make hourly location predictions
predTime <- seq(ceiling(min(nfsNew$Time)), floor(max(nfsNew$Time)), 1)
predObj <- crwPredict(object.crwFit=fit, predTime=predTime, speedEst=TRUE,
flat=FALSE)
str(predObj)
predObj <- as.flat(predObj)
head(predObj)
crwPredictPlot(predObj)