There are a number of ways in ggplot to express your data.  The first are the geometric objects:

• geom_bar(): Bar charts
• geom_point(): Points – great for scatter plots
• geom_line(): Line charts
• geom_boxplot(): A box & whiskers plot
• geom_smooth(): Smoothed means with CI
• geom_histogram(): Histogram
• geom_density(): Smoothed density plot
• geom_qq(): A quantile-quantile plot
• geom_errorbar(): Error bars

All of these geoms (and more) are highly customizable.  But first we must set up the data. Continue reading →