[R] Unwanted boxes in legend

[Steve Murray]

Dear all,

I am using the following code to generate a legend in my plot (consisting of both bars and points), but end up with boxes around my points:

legend(10, par("usr")[4], c("A", "B", "C", "D"), fill=c(NA,NA, "grey28", NA), pch=c(16,4,NA,18), col=c("red","blue","grey28","yellow"), lty=FALSE, bty="n", horiz=FALSE)

I want a box around the third element of the legend (to represent the bar 'fill' colour), but not for the others, where points are shown instead.

What am I doing wrong above and how do I correct it?

Many thanks,

Steve