3.1) plot(): A Versatile Function

The main function to use for graphs is plot(). Typing ?plot leads to a help file for this function that is deceptively brief: you’ll see that the main arguments are x= and y= (which must be equal-length vectors), and the Details section hints at how different kinds of objects can be handled. So if x and y are both numeric, you get a simple scatter plot. However, it turns out that if x is a factor, you’ll get a boxplot, or if y is a factor and x is continuous, you get a profile plot. If you don’t supply y, you get the values of x plotted against their order (assuming x is numeric, like a time series) – or a bar chart of the frequencies of each value of x (if x is a factor).
Let's try these...