R/frameIt.R

In KevCaz/graphicsutils: Collection of graphics utilities

#' Draw a frame around a plot
#'
#' Draw a frame around the plot region as an ensemble of small rectangles
#' whose colors can be specified.
#'
#' @param nbc number of rectangles to be drawn for each axis.
#' @param cex.x control the dimension
#' @param cex.y The radii of the circles.
#' @param col color of the rectangles drawn.
#' @param border color of the borders if the rectangles drawn.
#'
#' @keywords frame, box
#'
#' @export
#'
#' @details
#'
#' The number of rectangles could be different from `nbc` as `pretty` is called
#' to properly locate them. The `col` argument determines the succession of
#' colors to be applied to each axis.
#'
#' @examples
#' # Example 1:
#' plot0()
#' frameIt()
#'
#' # Example 2:
#' plot0()
#' frameIt(cex.x = 1.5, col = c(2, 3), border = 1)
#'
frameIt <- function(nbc = 10, cex.x = 1, cex.y = cex.x,
                    col = c("grey45", "grey85"), border = NA) {
    pu <- par()$usr
    ##
    px <- pretty(c(pu[1L], pu[2L]), nbc)
    dx <- px[2L] - px[1L]
    px <- c(px[1L] - dx, px, px[nbc] + dx)
    ##
    py <- pretty(c(pu[3L], pu[4L]), nbc)
    dy <- py[2L] - py[1L]
    py <- c(py[1L] - dy, py, py[nbc] + dy)
    ##
    widx <- 0.01 * (pu[4L] - pu[3L]) * cex.x * par()$pin[1L] / par()$pin[2L]
    widy <- 0.01 * (pu[2L] - pu[1L]) * cex.y
    ##
    mycol <- rep_len(col, nbc + 3)
    ##
    for (i in seq(1, nbc + 3)) {
        # axis 1
        rect(px[i], pu[3L], px[i + 1], pu[3L] + widx,
            col = mycol[i],
            border = border
        )
        # axis 3
        rect(px[i], pu[4L] - widx, px[i + 1], pu[4L],
            col = mycol[i],
            border = border
        )
        # axis 2
        rect(pu[1L], py[i], pu[1L] + widy, py[i + 1],
            col = mycol[i],
            border = border
        )
        # axis 4
        rect(pu[2L] - widy, py[i], pu[2L], py[i + 1],
            col = mycol[i],
            border = border
        )
    }
    invisible(NULL)
}