-- Copyright 2012 by Till Tantau -- -- This file may be distributed an/or modified -- -- 1. under the LaTeX Project Public License and/or -- 2. under the GNU Public License -- -- See the file doc/generic/pgf/licenses/LICENSE for more information -- @release $Header$ -- Imports local declare = require("pgf.gd.interface.InterfaceToAlgorithms").declare --- -- @section subsubsection {Forces and Their Effects: Springs} -- -- The most important parameter of springs is their ``natural -- length'', which can be configured using the general-purpose -- |node distance| parameter. It is the ``equilibrium length'' of a -- spring between two nodes in the graph. When an edge has this -- lenght, no forces will ``push'' or ``pull'' along the edge. -- -- The following examples shows how a simple graph can be scaled by -- changing the |node distance|: -- \begin{codeexample}[] -- \tikz \graph [spring layout, node distance=7mm] { subgraph C_n[n=3] }; -- \tikz \graph [spring layout] { subgraph C_n[n=3] }; -- \tikz \graph [spring layout, node distance=15mm]{ subgraph C_n[n=3] }; -- \end{codeexample} -- \begin{codeexample}[] -- \tikz \graph [spring electrical layout, node distance=0.7cm] { subgraph C_n[n=3] }; -- \tikz \graph [spring electrical layout] { subgraph C_n[n=3] }; -- \tikz \graph [spring electrical layout, node distance=1.5cm] { subgraph C_n[n=3] }; -- \end{codeexample} -- -- @end --- declare { key = "spring constant", type = "number", initial = "0.01", summary = [[" The ``spring constant'' is a factor from Hooke's law describing the ``stiffness'' of a spring. This factor is used inside spring-based algorithms to determine how strongly edges ``pull'' and ``push'' at the nodes they connect. "]] }