Points added to plot as rectangles

[joshuaulrich]

Points are represented with rectangles when added to a plot with either points() or addSeries(). It would be better to add them using a value for pch similar to plot(1:10, type = "p"). pch = 21 seems to produce a graph similar to base plotting.

require(xts)
data(sample_matrix)
x <- as.xts(sample_matrix)
plot(x[,1])
addSeries(x[,2], type = "p")
addSeries(x[,3], type = "b")
points(x[,4])