[R] Axis manipulation in Stackpoly (Plotrix)

[Ben Neal]

Have made a stacked area plot, but now want to manipulate the x axis: make in even increments (50) in order to suppress the tick marks (forming solid bar under plot). However, the plot functions do not seem to work, and I cannot find documentation for use of xat in stackpoly. 

This is a time series of data covering 579 years, and has been successfully converted from zoo to matrix. Data plotting fine, jsut want to change axis - 

CaribMatrix<-as.matrix(ts4Ex)
stackpoly(CaribMatrix, stack=TRUE, xlab="Year",ylab="Catch in tons", xaxlab=(1250:2008),
          main="Historical Florida reef fisheries catch by sector", axis4="FALSE")

Any assistance appreciated! Thanks very much, Benjamin P Neal, Scripps Inst. of Oceanogrpahy