A method sorts data in data visualizations. The method is performed at a computing device having one or more processors and memory. The method retrieves a set of tuples from a database according to user selection. Each tuple includes a same set of fields. The method identifies a relation between tuples. The relation is a non-empty set of ordered pairs of tuples from the set of tuples. The method receives user selection of the relation to specify a dimensional position of visual marks corresponding to the tuples. The dimensional position is either the x-position of the y-position. The method generates and displays a data visualization with each tuple represented by a visible mark. The dimensional position of each displayed visual mark is based on a network traversal of the tuples using the relation.