R/makePSData.R

In fitPS: Fit Zeta Distributions to Forensic Data

#' Create a survey data set manually
#'
#' Create a survey data set from the command line rather than reading data in
#' from a file. This function is likely to be only useful where there are a very
#' small number of group sizes, or sizes of groups of glass.
#'
#' @param n Either the number of groups of glass or the size of different groups
#'   of glass, or a \code{vector} of observed groups of glass, or group sizes.
#'   See details for a longer explanation.
#' @param count Either the number of people in the survey sample who had
#'   \eqn{n}{n} groups of glass on their clothing, or the number of people who
#'   had a group of glass of size \eqn{n}{n}.
#' @param type either \code{"P"} or \code{"S"}
#' @param notes a \code{\link[utils]{bibentry}} or a character string which
#'   allows extra information about the data to be stored, such as the source,
#'   or reference. \code{NULL} by default.
#'
#' @details If \code{count} is \code{NULL}, then it is assumed that \code{n}
#'   consists of actual observed group sizes or numbers of groups of glass found
#'   on a survey of N individuals. That is, one could provide \code{n = rep(0:1,
#'   98, 1)} or \code{n = 0:1, count = c(98, 1)}. The former is more useful when
#'   performing simulation studies.
#'
#'
#' @return an object of type \code{psData}---see \code{\link{readData}} for more
#'   details.
#'
#' @aliases makeData
#' @export
#'
#' @examples
#' ## recreate the data read in the readData example
#' p1 = makePSData(n = c(0, 1, 2), count = c(98, 1, 1), type = "P")
#' s1 = makePSData(n = 1:3, count = c(1, 1, 1), type = "S")
#' p1
#' s1
#'
#' @seealso readData
makePSData = function(n, count = NULL, type = c("P", "S"), notes = NULL){
  type = match.arg(type)

  if(is.null(count)){
    tbl = table(n)
    count = as.numeric(tbl)
    n = as.numeric(names(tbl))
  }

  dataf = data.frame(n = n, rn = count)

  if(any(dataf$rn <= 0)){
    stop("You must have at least one non-zero positive count")
  }

  if(type == "S" & any(dataf$n <= 0)){
    stop("The labels for group sizes must be 1 or greater")
  }else if(type == "P" & any(dataf$n < 0)){
    stop("The labels for group sizes must be 1 or greater")
  }

  if(any(dataf$n -floor(dataf$n) > 0) || any(dataf$rn -floor(dataf$rn) > 0)){
    dataf$n = round(dataf$n)
    dataf$rn = round(dataf$rn)
    warning("Non-integer input detected. Both input vectors have been rounded.")
  }

  result = list(type = type,
                data = dataf,
                notes = notes)
  class(result) = "psData"

  return(result)
}

#' @rdname makePSData
#' @export
makeData = makePSData

#' @rdname makePSData
#' @export
createPSData = makePSData