Thanks very much, Duncan. In case it's of interest to others who encounter
this thread later, I am pasting below the code I wrote. It is for the 'oce'
package for oceanographic data, which explains the reversal of the y axis,
forming a so-called 'profile', in which the top of the graph represents the
top of the water column.
args <- list(x=x$data$temperature, y=x$data$pressure,
xlim=range(x$data$temperature),
log="",
ylim=rev(range(x$data$pressure)),
xlab=expression(paste("Temperature [", degree, "C ]")),
ylab="p [dbar]", ...)
if (!("type" %in% names(list(...)))) args <- c(args, type="p")
if (!("cex" %in% names(list(...)))) args <- c(args, cex=0.3)
do.call(plot, args)