stationary.migration.summary function

find potential stationary periods and estimates their location and movement schedule

This function will find any sites where birds stayed longer than min.stay. Potential movement is detected by the minimum probability of movement prob.cutoff.

stationary.migration.summary(Result, prob.cutoff = 0.1, min.stay = 3)

Arguments

• Result: FLightR result object obtained from run.particle.filter
• prob.cutoff: Minimum probability that defines movement
• min.stay: Minimum duration of stationary period (in twilights)

Returns

list with stationary and movement statistics

Examples

File<-system.file("extdata", "Godwit_TAGS_format.csv", package = "FLightR")
# to run example fast we will cut the real data file by 2013 Aug 20
Proc.data<-get.tags.data(File, end.date=as.POSIXct('2013-06-25', tz='GMT'))
Calibration.periods<-data.frame(
       calibration.start=as.POSIXct(c(NA, "2014-05-05"), tz='GMT'),
       calibration.stop=as.POSIXct(c("2013-08-20", NA), tz='GMT'),
       lon=5.43, lat=52.93) 
       #use c() also for the geographic coordinates, if you have more than one calibration location
       # (e. g.,  lon=c(5.43, 6.00), lat=c(52.93,52.94))

# NB Below likelihood.correction is set to FALSE for fast run! 
# Leave it as default TRUE for real examples
Calibration<-make.calibration(Proc.data, Calibration.periods, likelihood.correction=FALSE)

Grid<-make.grid(left=0, bottom=50, right=10, top=56,
  distance.from.land.allowed.to.use=c(-Inf, Inf),
  distance.from.land.allowed.to.stay=c(-Inf, Inf))

all.in<-make.prerun.object(Proc.data, Grid, start=c(5.43, 52.93),
                             Calibration=Calibration, threads=1)
# here we will run only 1e4 partilces for a very short track.
# One should use 1e6 particles for the full run.
Result<-run.particle.filter(all.in, threads=1,
           nParticles=1e3, known.last=TRUE,
           precision.sd=25, check.outliers=FALSE)

Summary<-stationary.migration.summary(Result, prob.cutoff=1)
# Use lower cut offs for real runs!

Author(s)

Eldar Rakhimberdiev