Three stages of making a graph:
Statistical graphic specifications are expressed in six statements
- DATA: a set of data operations that create variables from datasets
- TRANS: variable transformations (e.g., rank)
- SCALE: scale transformations (e.g., log)
- COORD: a coordinate system (e.g., polar)
- ELEMENT: graphs (e.g., points) and their aesthetic attributes (e.g., color)
- GUIDE: one or more guides (axes, legends, etc.)
Assembling a scene from a specification requires a variety of structures in order to index and link components with each other. One of the structures we can use is a network or a tree.
Rendering the graphics.
Syntax of the Grammar of Graphics
- Create Variables: to extract data into variables
- Apply Algebra: a graphics algebra consisting of three operators — cross, blend and nest — applied to a set of variables, together with a set of associated rules
- Apply Scales: A categorical scale transformation associates the values of a categorical variable with the set of integers
- Compute Statistics: do some statistics on the data
- Construct Geometry: the grammar of graphics has a variety of different geometric graphing operations
- Apply Coordinates: to make pie wedges, we apply a polar transformation to the shapes that were produced from the geometry
- Compute Aesthetics: aesthetic functions translate a graph into a graphic
Planted: by LM;
L Ma (2020). 'Graph Creation', Datumorphism, 12 April. Available at: https://datumorphism.leima.is/reading/grammar-of-graphics/graph-creation/.