## none
library(Pyramid)
library(animation)
ani.options(interval = 0.8)
for (i in 1:3) {
    Pyramid(Porter.male[, i], Porter.female[, i], widths = widths, 
        fill.male = "aquamarine3", fill.female = "orange", 
        border.male = "black", border.female = "black", main = "Porter City, Yellow Medicine County Population: 1990, 2000, 2010")
}
## R version 2.15.0 (2012-03-30)
## Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)
## Other packages: Pyramid 1.2, animation 2.0-6