| 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' |
...
....
~~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)
}