Chu's Space

my.minor.tick <-
function (nx = 2, ny = 2, tick.ratio = 0.5, side=NA)  
{ # added the side parameter
    ax <- function(w, n, tick.ratio) {
        range <- par("usr")[if (w == "x") 
            1:2
        else 3:4]
        tick.pos <- if (w == "x") 
            par("xaxp")
        else par("yaxp")
        distance.between.minor <- (tick.pos[2] - tick.pos[1])/tick.pos[3]/n
        possible.minors <- tick.pos[1] - (0:100) * distance.between.minor
        low.minor <- min(possible.minors[possible.minors >= range[1]])
        if (is.na(low.minor)) 
            low.minor <- tick.pos[1]
        possible.minors <- tick.pos[2] + (0:100) * distance.between.minor
        hi.minor <- max(possible.minors[possible.minors <= range[2]])
        if (is.na(hi.minor)) 
            hi.minor <- tick.pos[2]
        if (.R.)        # Next three lines have only the modifications
            axis(if (w == "x" & is.na(side) )
                1
            else if (!is.na(side)) side
            else 2, seq(low.minor, hi.minor, by = distance.between.minor), 
                labels = FALSE, tcl = par("tcl") * tick.ratio)
        else axis(if (w == "x") 
            1
        else 2, seq(low.minor, hi.minor, by = distance.between.minor), 
            labels = FALSE, tck = par("tck") * tick.ratio)
    }
    if (nx > 1) 
        ax("x", nx, tick.ratio = tick.ratio)
    if (ny > 1) 
        ax("y", ny, tick.ratio = tick.ratio)
    invisible()
}

上面如果运行不正常，可以试试下面的代码：

environment(my.minor.tick) <- environment(minor.tick)

转自：http://stackoverflow.com/questions/17118360/does-minor-tick-of-library-hmisc-in-r-only-work-for-primary-axis-side-1-and-2