Vertex Position Encoding

A unique feature in Data Illustrateur is the ability to bind data to the properties of vertices and segments. This feature is useful for visualization designs that may be hard to describe using only shape properties. The behavior of data binding varies, depending on whether the vertices are drawn by hand, or generated by the densify action.

Vertices Drawn by Hand#

When you use the Line Tool or the Path Tool to draw a path, the vertices are drawn by hand. Even if you repeat the path by data, Data Illustrateur still considers the vertices on the repeated paths drawn by hand. Data Illustrateur currently does not allow binding data to vertices in rectangles, pies and arcs.

The following example illustrates binding data to hand-drawn vertices to create a triangle bar chart. We first use the Pen Tool to draw a triangle, repeat it by “Country”, then we use the Direct Select Tool to select the top vertex. All the vertices that will be bound to data are highlighted. We bind the y positions of the vertices to the variable “Count”. Note that here data binding only affects the top vertex in each triangle, the other vertices in the triangles are not affected.

Vertices in Densified Path#

When you densify a line by data, the vertices are generated and associated with data. The binding action will apply to all the vertices on the path. In the example below, we create a small multiple of line graphs, where each line represents the stock price of a company over time. We first perform the repeat action on a line, which places the lines in a grid layout. Each line represents a “company”. We then densify the lines by “Date”. Finally, we bind “date” to the x positions of the vertices, and “price” to the y positions of the vertices. The final result is a set of line graphs, placed in a grid. You can change the layout parameters to arrange the line graphs in different ways.

Given the small multiple, we can also change the layout of the collection to “None” so that the line graphs share the same axis. Once the layout is removed, Data Illustrateur automatically unifies the scales of the line graphs, creating a multi-line graph.