layout.circle Function (GPL)
Syntax
layout.circle(<function>))
or
layout.circle(<algebra>, <function>)
<algebra>. Graph algebra, such as x*y
.
Refer to Brief Overview of GPL Algebra for an introduction to graph algebra. The algebra
for network graphs is 1*1
because the position of
elements is determined by the layout method and is not tied to a coordinate
value (such as a value on a dimension). This algebra is implied and
needs to be specified for network graphs only when faceting is needed.
<functions>. Valid functions. The from
and to
functions
are required. The node
function is optional for edges,
allowing you to draw edges without a separate node data source.
Description
Lays out graphic elements in a circle. The function is used for network graphs, which are visual representations of data that consist of nodes and relations between nodes (edges). The circle l layout is a layout that can be applied to any graph. It lays out a graph assuming that links are undirected and treats all nodes identically. Nodes are placed only around the perimeter of a circle
Note: Network
graphs that display nodes and edges require two data sources, one for the
unique nodes and one for the edges. If the edge data source includes weights
and the weight variable is indicated in the SOURCE
statement,
the weights influence the length of edges in the graph, with higher weights
having shorter edges.
Examples
ELEMENT: edge(position(layout.circle(node(id), from(fromVar), to(toVar))))
ELEMENT: point(position(layout.circle(node(id), from(fromVar), to(toVar))), label(id))