bar plot of DGD1, Bartle and control population percentages

types <- c("Conqueror","Manager","Wanderer","Participant")
mycolors <- c(rgb(0.1,0.1,0.1), rgb(0.5,0.5,0.5), rgb(0.8,0.8,0.8))
survey <- c(15.5,27.5,45,12)
bartle <- c(31,27,25.5,15.5)
control <- c(24,16.5,29.5,30)
data <- rbind(survey,bartle,control)

#adjust margins
par(mar=c(2.5,4.5,1,1))

# http://stat.ethz.ch/R-manual/R-patched/library/graphics/html/barplot.html
barplot(data, beside=TRUE,
    ylab="Percent of respondents",
    names.arg=types, ylim=c(0,50), col=mycolors)

# grid only in y-direction
# http://stat.ethz.ch/R-manual/R-patched/library/graphics/html/grid.html
grid(NA, 10)

# legend at the top-left corner
legend("topleft", c("Survey","Bartle","Control"), cex=1.3, bty="n", fill=mycolors);