The generation of plots in the analysis facility is done using a data structure known as a selection. A selection consists of a list of data points associated with a position number, residue number, and a residue name (more detail is available in the description of the SELECT command below and the introduction, see Introduction to Analysis). Data for a selection comes from the table, see Tables. All plots are generated from the selection. Two such data structures are provided allowing scatter plots to be produced as well.