[R] Remove all box around a plot except bottom line (base graphics)

[Martin Maechler]

>>>>> Michael Dewey 
>>>>>     on Thu, 28 Nov 2024 15:27:59 +0000 writes:

    > Thank you Duncan, I will try that next.
    > Michael

    > On 28/11/2024 13:52, Duncan Murdoch wrote:
    >> On 2024-11-28 8:36 a.m., Michael Dewey wrote:
    >>> To make the plot clearer I have removed the axes but I wish to remove
    >>> all the boz except the bottom horizontal line. Using the bty parameter
    >>> does not seem to enable me to just leave the horizontal line at the
    >>> foot. I can get the "l" version to remove everything except the left
    >>> hand side and the base. I could also remove the entire box but that
    >>> looks odd. Am I reading the documentation incorrectly or is it really
    >>> impossible?
    >>> 
    >> 
    >> It's not something that `bty` can specify or `box()` can do, but you can 
    >> draw a line using lines() or segments().  For example:
    >> 
    >>  plot(rnorm(100), yaxt="n", bty="n")
    >>  usr <- par("usr")
    >>  lines(usr[c(1,2)], usr[c(3,3)], xpd = TRUE)
    >> 
    >> You might not even need the lines() call if you don't care how far the 
    >> axis extends.
    >> 
    >> Duncan Murdoch

also, if like in this example, you are talking about using  plot.default()
{or something that *calls* plot.default() eventually, such as
 plot.formula() ...}

you might want to play with  frame.plot = FALSE  :

    plot(rnorm(50), frame.plot=FALSE, yaxt="n")

maybe what you want?  {a bit more efficient internally than 'bty = "n"'}

Martin