"plot"(x, xylim="auto",clab=1:nrow(X),lab.cex=1,lab.col="black",...)
xylim[1,1]
, xylim[1,2]
) of the plot.
The y limits (xylim[2,1]
, xylim[2,2]
) of the plot.
Note that xylim[i,1]
> xylim[i,2]
(i=1, 2) is allowed and leads to a 'reversed axis'.