Edge Attributes

This section describes the whole list of edge attributes. Each attribute is listed together with its type and default value.

• anchor   
  Type: integer
  Default value: no default value
  Attribute of: edge
  Description:
  An anchor point describes the vertical position in a node where an edge starts. This is useful if node labels are several lines long and outgoing edges are related to label lines. (For instance, this allows a nice visualization of structs containing pointers as fields).

• arrowcolor, backarrowcolor      
  Type: black, blue, red, ...
  Default value: value of the color attribute for both
  Attribute of: edge
  Description:
  Respectively the color of the arrow head or backarrow head. For details on colors, see section Colors. See also edge attributes textcolor and color.

• arrowsize, backarrowsize      
  Type: integer
  Default value:
  10 pixels for the arrowsize and
  0 pixels for the backarrowsize
  Attribute of: edge
  Description:
  The arrow head is a right-angled, isosceles triangle. These two attributes respectively specify the length of the cathetuses of the arrow head and back arrow head.

• arrowstyle, backarrowstyle      
  Type: none, solid, line
  Default value:
  solid for the arrowstyle and
  none for the backarrowstyle
  Attribute of: edge
  Description:
  Each edge has two arrow heads, one arrow head pointing to the target node, called normal arrow head, and the other one "pointing" to the source node, called back arrow head. arrowstyle is the style of the normal arrow head and backarrowstyle the style of the back arrow head. The styles are:
  • none
      No arrow head is drawn.
  • solid
      Arrow head is filled with edge color.
  • line
      Arrow head is not filled and drawn without the hypotenuse of the triangle forming the head.
  The default edges have a solid arrow head and no back arrow head.

• class   
  Type: integer
  Default value: 1
  Attribute of: edge
  Description:
  This attribute specifies the edge class to which an edge belongs. For details, see edge classes and the grouping of nodes in general ( groups of nodes).

• color   
  Type: black, blue, red, ...
  Default value: black
  Attribute of: edge
  Description:
  Here the color attribute specifies the color of the edge. For details on colors, see section Colors. See also edge attributes textcolor and arrowcolor.

• fontname   
  Type: string
  Default value: default font is drawn by turtle graphics routines
  Attribute of: node
  Description:
  This attribute specifies a pixel font which is different from the default font and to be used for drawing the edge labels. This font is given by the name of the aiSee font file that containing the font description, for example a 12-point Times Roman font can be specified via fontname: "timR12.vcf". Note: If the font file is not in the current directory the environment variable AISEEFONTS has to be set to the directory containing the font description files.   For details on fonts, see additional fonts.

• horizontal_order   
  Type: integer
  Default value: unspecified
  Attribute of: edge
  Description:
  In a hierarchical layout, this attribute specifies the horizontal position of long edges. This is only of interest if an edge crosses several levels (see node attribute horizontal_order). This attribute specifies the point where the edge crosses the level.

  The nodes specified by horizontal positions are ordered according to these positions within a level. The horizontal position of a long edge crossing a level specifies the two nodes of the level between which the edge has to be drawn. Other edges not possessing this attribute are inserted in this ordering by the crossing reduction mechanism (see crossing reduction).

• label   
  Type: string
  Default value: empty string
  Attribute of: edge
  Description:
  This attribute specifies the text label of an edge. It is drawn if the graph attribute display_edge_labels is set to yes.

  Note: This string may contain control characters, e.g. \n (newline character), that influence the size of the label. See Character Set for more details.

• linestyle   
  Type: continuous, dashed, dotted, double, invisible, solid, triple
  Default value: continuous
  Attribute of: edge
  Description:
  This attribute specifies the style in which an edge is drawn. The following possibilities are offered:
  • continuous    
    The edge is drawn as a solid line (---).

  • dashed    
    The edge consists of single dashes (- - -).
  • dotted    
    The edge consists of single dots ( ... ).
  • double    
    The edge consists of a solid double line ( === ).
  • invisible    
    The edge is not drawn. The attributes of its shape (color, thickness) are ignored.
  • solid    
    The edge is drawn as a solid line (same as continuous parameter).

  • triple    
    The edge consists of a solid triple line ( $\equiv$ ).

• priority   
  Type: integer
  Default value: 1
  Attribute of: edge
  Description:
  The positions of the nodes are mainly determined by the incoming and outgoing edges. The edges can be imagined as rubberbands pulling a node to its position. The priority of an edge corresponds to the strength of the imaginary rubberband acting on it.

• sourcename   
  Type: string
  Default value: no default
  Attribute of: edge
  Description:
  This attribute specifies the title of the source node of an edge. It is mandatory for the edge specification.

• targetname   
  Type: string
  Default value: no default
  Attribute of: edge
  Description:
  This attribute specifies the title of the target node of an edge. It is mandatory for the edge specification.

• textcolor   
  Type: black, blue, red, ...
  Default value: value of the color attribute
  Attribute of: edge
  Description:
  Specifies the color of the text label of an edge. For details on colors, see section Colors. See also node attributes color and arrowcolor.

• thickness   
  Type: integer
  Default value: 2
  Attribute of: edge
  Description:
  Specifies the thickness of an edge.

Last modified on 11 August 2003 by webmaster. © 2000-2003 AbsInt