R/itpPrint.R

In itp: The Interpolate, Truncate, Project (ITP) Root-Finding Algorithm

#' Print method for objects of class \code{"itp"}
#'
#' Prints objects of class \code{"itp"} returned from \code{\link{itp}}.
#' @param x An object inheriting from class \code{"itp"}, a result of a
#'   call to \code{\link{itp}}.
#' @param all A logical scalar.  If \code{all = FALSE} then only the estimated
#'   root, the value of the function at the root an the number of iterations
#'   are printed.  If \code{all = TRUE} then, in addition, the final bracketing
#'   interval [\code{a, b}], the values of the function at the end points of
#'   this interval and the estimated precision are printed.
#' @param digits The argument \code{digits} passed to \code{\link{format}}
#'   to set the number of significant digits to print.
#' @param ... Further arguments to be passed to or from other methods. They are
#'   ignored in this function..
#' @details The default setting is to print only the root, the value of the
#'   function at the root and the number of iterations.  To include the
#'   bracketing interval after convergence and the estimated precision use
#'   \code{all = TRUE}.
#'
#' @return The argument \code{x} is returned, invisibly.
#' @seealso \code{\link{itp}} for the Interpolate, Truncate, Project (ITP) root
#'   finding algorithm.
#' @export
print.itp <- function(x, all = FALSE,
                      digits = max(3L, getOption("digits") - 3L), ...) {
  temp <- x
  names(temp) <- c("root", "f(root)", "iterations", "a", "b", "f.a", "f.b",
                   "precision")
  cat("function:", attr(x, "f_name"), "\n")
  if (!all) {
    print.default(format(temp[1:3], digits = digits), print.gap = 2L,
                  quote = FALSE)
  } else {
    print.default(format(temp[1:8], digits = digits), print.gap = 2L,
                  quote = FALSE)
  }
  invisible(x)
}