Options of the graph layouter

The main parameters of the layout algorithm are optional and can be initialized or set in the layouter's option dialog which is available by menu Preferences / Options... and shown in Figure 13.

The options are explained here:

• Setting perform during graph transformation - if selected, the new layout algorithm is used to layout the transformed graphs.

• Setting write to directory - if selected, each graph of the graph transformation sequence is converted to JPEG image (.jpg) and written to a user defined directory. The directory can be chosen before the transformation by a file chooser dialog.

• Setting write to (.log) file - if selected, the layout metrics are written into a <name>.log file in a user defined derectory (see write to directory).

• Setting iteration count of layout process - is used to set the count of iterations to run. Use RETURN key to accept the changes.

• Setting initial temperature of cooling - is used to set an initial temperature $t(0)$ for the initial layout. Use RETURN key to accept the changes.

• Setting preferred edge length - defines the preferred length for all edges of the transformed graphs. Use RETURN key to accept the changes.

• Setting use layout pattern - enables the Graph Layout Pattern area of this option dialog. If selected, a user can define or change an edge type pattern, that would be used for layout. If this option isn't selected, the only default layout pattern of this algorithm are used, but no user defined pattern.

• Setting Selected Edge Type - defines the type for the edge type layout patterns.

• Section Edge Type Layout Pattern - it allows to define at most three patterns: one for X-, one for Y-axis and one for edge length.

• Setting preferred length - defines edge length pattern. In general, a similar distance between child nodes is caused by the spring embedder layout and should not be described by a pattern itself. Use RETURN key to accept the changes.

• Table of Graph Layout Patterns - this table shows all user defined patterns for all edge types.
  

Finally, it is possible to stop any node mobility (see Freezing age concept) of each node individually. We can do this by choosing item Graph Layout from the pop-up menu Operations and selecting item Static Position.