R/abdData.R

In kmiddleton/abd: The Analysis of Biological Data

#' Find data in \emph{Analysis of Biological Data}
#'
#' A utility function to assist users to locate data sets in \emph{Analysis of
#' Biological Data} within the \code{abd} package.
#'
#'
#' @param \dots values for any of \code{chapters}, \code{types}, or
#' \code{pattern}.  Which is meant will be inferred from the type of object
#' supplied.  This allows users to specify these values in any order and
#' without naming.
#' @param chapters a numeric vector of chapters to search within
#' @param types a sub-vector of c('Example','Problem')
#' @param numbers a numeric vector of problem numbers
#' @param pattern a pattern to use for regular expression matching against the
#' name of the data frame.
#' @param ignore.case should case be ignored when matching pattern?
#' @return A data frame describing data sets from \code{abd} that match the
#' search criteria, or NULL if there are no matches.
#' @author Randall Pruim (\email{rpruim@@calvin.edu})
#' @keywords datasets
#' @export
#' @examples
#'
#' # find all data from examples in chapters 3 and 4
#' abdData(3:4, "Example")
#'
#' # order doesn't matter
#' abdData("Example", 3:4)
#'
#' # look for data sets with Example in their name.
#' abdData(pattern="Example")
#'
#' # look for data sets with Exercise in their name.
#' abdData("Exercise")
#'
abdData <- function(...,
                    chapters = 1:21,
                    types = c("Example", "Problem"),
                    numbers = 1:100,
                    pattern = "*",
                    ignore.case = TRUE) {

  dots <- list(...)

  for (x in dots) {
    if ( all( x %in% c("Example","Problem") ) ) {
      types <- x
    } else {
      if (is.character(x)) {
        pattern <- x
      } else {
        if (is.numeric(x)) {
          chapters <- x
        }
      }
    }
  }

  results <- with(
    abd::dataInfo,
    dataInfo[chapter %in% chapters &
               type %in% types &
               number %in% numbers &
               grepl(pattern,
                     name,
                     ignore.case = ignore.case), ])

  if (prod(dim(results)) == 0) {
    return (NULL)
  }
  return(results)
}