R/eq01buildW0vect.R

In brouwern/FACavian: An R implementation and extension of full-annual cycle (FAC) model of Runge & Marra *2005)

#' Equation 1: Set up current population vector (W0)
#'
#' Create a vector representing population structure at the beginning of winter (W0) after competition for territories has occured but before winter mortality.
#'
#' During 1st iteration (\code{i=1}) the population status is taken from the \code{runFAC()} function call as it was set by the user.  \code{W0} is then updated during every iteration by taking values of \code{W.mg}, \code{W.mp}, etc that were calculated in Equation 27 at the end of the last iteration (\code{i-1})
#'
#' Formalizing this into an equation may not be strictly necessary but helps with aliginging how the model is implemented in \code{redstart} how it is described in the original Runge and Marra (2004) paper.
#'
#' @param W.mg Number of males (.m_) wintering in good (._g) habitat.  Scalar
#' @param W.mp Number of males (.m_) wintering in poor (._p) habitat.  Scalar
#' @param W.fg Number of females (.f_) wintering in good (._g) habitat. Scalar
#' @param W.fp Number of males (.f_) wintering in poor (._p) habitat. Scalar
#'
#' @return W0 A vector containing the status of the population at the beginning of winter: \code{W.mg} , \code{W.mp} , \code{W.fg} , and \code{W.fp}
#'
#' @references Runge, MC and PP Marra.  2004.  Modeling seasonal interactions in the population dynamics of migratory birds. In Greenberg, R and PP Marra, eds.  Birds of two worlds. Johns Hopkins University Press, Baltimore.
#'
#' @examples
#' eq01buildW0vect(W.mg = 10, W.mp = 10, W.fg = 10, W.fp = 10)
#'
#' @export


eq01buildW0vect <- function(W.mg, W.mp,
                            W.fg, W.fp){

  W0        <- c(W.mg, W.mp, W.fg, W.fp)
  names(W0) <- c("mg","mp","fg","fp")

  return(W0)
}