simm.bb {adehabitat} | R Documentation |
~~ A concise (1-5 lines) description of what the function does. ~~
simm.bb(date = 1:100, begin = c(0, 0), end = begin, id = "A1", burst = id)
date |
~~Describe date here~~ |
begin |
~~Describe begin here~~ |
end |
~~Describe end here~~ |
id |
~~Describe id here~~ |
burst |
~~Describe burst here~~ |
~~ If necessary, more details than the description above ~~
~Describe the value returned If it is a LIST, use
comp1 |
Description of 'comp1' |
comp2 |
Description of 'comp2' |
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~~further notes~~
~Make other sections like Warning with section{Warning }{....} ~
~~who you are~~
~put references to the literature/web site here ~
~~objects to See Also as help
, ~~~
##---- Should be DIRECTLY executable !! ---- ##-- ==> Define data, use random, ##-- or do help(data=index) for the standard data sets. ## The function is currently defined as function(date=1:100, begin = c(0,0), end=begin, id="A1", burst=id) { class(date) <- c("POSIX","POSIXct") n <- length(date) dt <- c(diff(unclass(date)),NA) dx <- c(rnorm(n-1,0,sqrt(dt[-n])),NA) dy <- c(rnorm(n-1,0,sqrt(dt[-n])),NA) W <- cbind(dx,dy) xtmp <- begin x <- begin for (i in 2:(n-1)) { a <- diag(1/(date[n]-date[i-1]),2) dX <- as.numeric((a%*%(end - xtmp)*dt[i-1] + W[i-1,])) x <- rbind(x,xtmp+dX) xtmp <- xtmp+dX } x <- rbind(x,end) res <- as.ltraj(data.frame(x[,1],x[,2]),date, id, burst) return(res) }