The circle packing algorithm is basically a treemap using circles instead of rectangles. Due to the nature of circles they cannot be packed as efficiently leading to increased amount of "empty space" as compared to a treemap. This can be beneficial though, as the added empty space can aid in visually showing the hierarchy.
layout_tbl_graph_circlepack( graph, weight = NULL, circular = FALSE, sort.by = NULL, direction = "out" )
An optional node variable to use as weight. Will only affect the weight of leaf nodes as the weight of non-leaf nodes are derived from their children.
Logical. Should the layout be transformed to a circular representation. Ignored.
The name of a node variable to sort the nodes by.
The direction of the tree in the graph.
means that parents point towards their children, while
'in' means that
children point towards their parent.
A data.frame with the columns
circular as well as any information stored as node
variables in the tbl_graph object.
Circle packing is a layout intended for trees, that is, graphs where nodes only have one parent and zero or more children. If the provided graph does not fit this format an attempt to convert it to such a format will be made.
Wang, W., Wang, H. H., Dai, G., & Wang, H. (2006). Visualization of large hierarchical data by circle packing. Chi, 517-520.
Welzl, E. (1991). Smallest enclosing disks (balls and ellipsoids). New Results and New Trends in Computer Science, 359-370.