r - How to add axis labels to a simple.scatterplot (UsingR) -

the package usingr has great out of box plotting tools. however, using simple.scatterplot function can't figure out how add axis labels.

library(usingr)  simple.scatterplot(iris$sepal.length, iris$sepal.width, xlab='hello axis')  error in plot.default(x, y, xlim = xrange, ylim = yrange, xlab = "x",  :    formal argument "xlab" matched multiple actual arguments 

the graph can of course produced without using xlab arg, , tried using mtext command, label ends in middle of page.

mtext(side=1, text='hello axis') 

i tried editing function without success either:

mysimple.scatterplot <- function (x, y)  {   def.par <- par(no.readonly = true)   n <- length(x)   xhist <- hist(x, sqrt(n), plot = false)   yhist <- hist(y, sqrt(n), plot = false)   top <- max(c(xhist$counts, yhist$counts))   xrange <- c(min(x), max(x))   yrange <- c(min(y), max(y))   nf <- layout(matrix(c(2, 0, 1, 3), 2, 2, true), c(3, 1),                 c(1, 3), true)   layout.show(nf)   par(mar = c(3, 3, 1, 1))   plot(x, y, xlim = xrange, ylim = yrange, xlab = 'hello x-axis', ylab = 'hello y-axis',         ...)   abline(lm(y ~ x))   par(mar = c(0, 3, 1, 1))   barplot(xhist$counts, axes = false, ylim = c(0, top), space = 0,            col = gray(0.95))   par(mar = c(3, 0, 1, 1))   barplot(yhist$counts, axes = false, xlim = c(0, top), space = 0,            col = gray(0.95), horiz = true)   par(def.par) } 

the cause here:

layout.show(nf) par(mar = c(3, 3, 1, 1)) # <-- here plot(x, y, xlim = xrange, ylim = yrange, xlab = 'hello x-axis', ylab = 'hello y-axis',       ...) 

the margins changed small value labels not in plot, outside of area.