graphical ->layout: attract=[real],
nominal=[real], repel=[real], adapt=[int], iterations=[int],
area=[area], network=[chain], move_only=[chain]When graphical is member of a network (see graphical<-network)
of connected graphicals (see graphical->connect),
this method tries to give the entire graph of connected graphicals a
sensible layout. Don't expect too much: this algorithm does not know
anything about what your graph is representing.
The algorithm is based on [Eades:84]. It defines a number of springs
between connected and non-connected nodes. The algorithm does a
Monte-Carlo simulation using these springs.
The parameters are:
- attract: real, default is 2
Strength of the springs
- nominal: real, default is 30
Natural Length of the springs. Individual connection
objects may have their specific connection
<-ideal_length
- repel: real, default is 2
.0 Force
(outwards) between any pair of non-connected graphicals
- adapt: int, default is 15 Determines how much the network is changed
each iteration
- iterations: int, default is 100 Determines the number of iterations.
- area: area Area in which to constrain the graph. By default the
graph extends unconstrained. window
<-visible
is often used to confine the graph to the visible part of a window
object.
- network: chain Network to layout. By default these are the
graphicals that can be reached using graphical
<-network.
If provided explicitely only the provided graphicals are affected.
Notably providing all nodes in a window and using window<-visible
for the area argument will layout each network and spread the separated
networks over the window.
- move_only: chain If present, only the given nodes are moved. This is
useful for adding nodes to a given graph without changing the layout of
the already displayed nodes.
Connections between objects are found using graphical<-connected,
which may be refined to deal with application specific situations.
Visible annimation can be achieved calling this predicate in a loop
using a low number of iterations each time and force a display update
using
graphical->flush between each iteration.
Defaults: See description
Bugs:
# Gets slow if there are many nodes (> 50).
- Produces bad results on large networks with many connections. @see graphical
->connect
@see class tree @see graphical<-network
@see topic Connections
