gtable is a layout engine built on top of R’s grid package that abstracts the creation of potentially nested grids of viewports for placing graphic objects. It serves as the layout engine powering ggplot2 and is used extensively by many R plotting functions.
The package makes it easy to ensure alignment of graphic elements and enables piecemeal composition of complex graphics. It provides a systematic way to manage grid layouts through a collection of graphic elements along with their placement in the grid and the grid’s dimensions. Graphic elements can span multiple rows and columns and can themselves be gtables, allowing for complex automatically arranging layouts.
