A replacement for R's "axis()" function that uses intersecting axes rather than the ugly stand-alone axes.

intersecting.axis.R

intersecting.axis <- function(side, at = NULL, labels = TRUE,
    line = NA, pos = NA, outer = FALSE, lty = "solid",
    lwd = 1, lwd.ticks = lwd, col = NULL, col.ticks = NULL,
    hadj = NA, padj = NA, ...) {
  if (! outer) {
    x.range <- extendrange(par("usr")[1:2],f=-0.01)
    y.range <- extendrange(par("usr")[3:4],f=-0.01)
    pos <- NA
    xline <- c(NA,NA)
    yline <- c(NA,NA)
    switch(side,
      { xline <- x.range; yline <- rep(min(y.range),2); pos <- min(y.range) },
      { xline <- rep(min(x.range),2); yline <- y.range; pos <- min(x.range) },
      { xline <- x.range; yline <- rep(max(y.range),2); pos <- max(y.range) },
      { xline <- rep(max(x.range),2); yline <- y.range; pos <- max(x.range) })
    lines(xline,yline,lwd=lwd,lty=lty)
    axis(side,pos=pos,lwd=0,lwd.ticks=lwd.ticks,col.ticks=col.ticks,at=at,labels=labels,...)
  } else {
    stop("Not implemented for 'outer = TRUE'.")
  }
}