Family tree layout with Dot/GraphViz

Question

I am trying to draw a family tree with Dot and GraphViz.

This is what I currently have:

# just graph set-up
digraph simpsons {
ratio = "auto"
mincross = 2.0

# draw some nodes
"Abraham"   [shape=box, regular=1, color="blue"] ;
"Mona"      [shape=box, regular=1, color="pink"] ;
"Clancy"    [shape=box, regular=1, color="blue"] ;
"Jackeline" [shape=box, regular=1, color="pink"] ;
"Herb"      [shape=box, regular=1, color="blue"] ;
"Homer"     [shape=box, regular=1, color="blue"] ;
"Marge"     [shape=box, regular=1, color="pink"] ;
"Patty"     [shape=box, regular=1, color="pink"] ;
"Selma"     [shape=box, regular=1, color="pink"] ;
"Bart"      [shape=box, regular=1, color="blue"] ;
"Lisa"      [shape=box, regular=1, color="pink"] ;
"Maggie"    [shape=box, regular=1, color="pink"] ;
"Ling"      [shape=box, regular=1, color="blue"] ;
# creating tiny nodes w/ no label, no color
"ParentsHomer" [shape=diamond,style=filled,label="",height=.1,width=.1] ;
"ParentsMarge" [shape=diamond,style=filled,label="",height=.1,width=.1] ;
"ParentsBart"  [shape=diamond,style=filled,label="",height=.1,width=.1] ;

# draw the edges
"Abraham"      -> "ParentsHomer" [dir=none, weight=1] ;
"Mona"         -> "ParentsHomer" [dir=none, weight=1] ;
"ParentsHomer" -> "Homer"        [dir=none, weight=2] ;
"ParentsHomer" -> "Herb"         [dir=none, weight=2] ;
"Clancy"       -> "ParentsMarge" [dir=none, weight=1] ;
"Jackeline"    -> "ParentsMarge" [dir=none, weight=1] ;
"ParentsMarge" -> "Marge"        [dir=none, weight=2] ;
"ParentsMarge" -> "Patty"        [dir=none, weight=2] ;
"ParentsMarge" -> "Selma"        [dir=none, weight=2] ;
"Homer"        -> "ParentsBart"  [dir=none, weight=1] ;
"Marge"        -> "ParentsBart"  [dir=none, weight=1] ;
"ParentsBart"  -> "Bart"         [dir=none, weight=2] ;
"ParentsBart"  -> "Lisa"         [dir=none, weight=2] ;
"ParentsBart"  -> "Maggie"       [dir=none, weight=2] ;
"Selma"        -> "Ling"         [dir=none, weight=2] ;
}

If I run this through dot (dot simpsons.dot -Tsvg > simpsons.svg), I get the following layout:

However, I'd like the edges to be more "family tree"-like: a T-junction between two married persons with the vertical line of the T again branching in an upside-down T-junction with small subdivisions for each of the children, like this mock-up, done in KolourPaint:

What is the dot syntax that I have to use to achieve this?

Answer 1

To do this in graphviz is fairly straightforward; there are a couple of syntax patterns you need: (i) syntax to represent the line-to-line connection (the "T"-junction in your plots above); (ii) syntax to enforce the hierarchical structure (i.e., nodes of same generation on the same plane on the vertical axis). It's easier to show:

digraph G {
    nodesep=0.6;
    edge [arrowsize=0.3];

    "g1" -> "g2" -> "g3" -> "g4"

    { rank = same;
        "g1"; "King"; "ph1"; "Queen";
    };

    { rank = same; 
        "g2"; "ph2"; "ph2L"; "ph2R"; "ph2LL"; "ph2RR"
    };

    { rank = same;
        "g3"; "ps1"; "ps2"; "pr1"; "pr2"
    };

    "King" -> "ph1" [arrowsize=0.0];
    "ph1" -> "Queen" [arrowsize=0.0];

    "ph1" -> "ph2" [arrowsize=0.0];
    "ph2LL" -> "ph2L" [arrowsize=0.0];
    "ph2L" -> "ph2" [arrowsize=0.0];
    "ph2" -> "ph2R" [arrowsize=0.0];
    "ph2R" -> "ph2RR" [arrowsize=0.0];

    "ph2LL" -> "ps1" [arrowsize=0.0];
    "ph2L"-> "pr1" [arrowsize=0.0];
    "ph2R" -> "ps2" [arrowsize=0.0];
    "ph2RR" -> "pr2" [arrowsize=0.0];

}

The code above will produce the graph below (i omitted the code i used to color the nodes). I left vislble the "guide" on the left (g1->g2....) just to show you how i enforced the positions among nodes of equal rank, you'll probably want to make it invisible in your own plots. Finally, the nodes with the labels beginning with 'ph' are the placeholder nodes for the "T-junctions."

Answer 2

I'm almost there, inspired by an old response on the graphviz-interest mailinglist and doug's answer.

The following code:

digraph G {
  edge [dir=none];
  node [shape=box];

  "Abraham"   [shape=box, regular=1, color="blue"] ;
  "Mona"      [shape=box, regular=1, color="pink"] ;
  "Clancy"    [shape=box, regular=1, color="blue"] ;
  "Jackeline" [shape=box, regular=1, color="pink"] ;
  "Herb"      [shape=box, regular=1, color="blue"] ;
  "Homer"     [shape=box, regular=1, color="blue"] ;
  "Marge"     [shape=box, regular=1, color="pink"] ;
  "Patty"     [shape=box, regular=1, color="pink"] ;
  "Selma"     [shape=box, regular=1, color="pink"] ;
  "Bart"      [shape=box, regular=1, color="blue"] ;
  "Lisa"      [shape=box, regular=1, color="pink"] ;
  "Maggie"    [shape=box, regular=1, color="pink"] ;
  "Ling"      [shape=box, regular=1, color="blue"] ;

  a1 [shape=circle,label="",height=0.01,width=0.01];
  b1 [shape=circle,label="",height=0.01,width=0.01];
  b2 [shape=circle,label="",height=0.01,width=0.01];
  b3 [shape=circle,label="",height=0.01,width=0.01];
  {rank=same; Abraham -> a1 -> Mona};
  {rank=same; b1 -> b2 -> b3};
  {rank=same; Herb; Homer};
  a1 -> b2
  b1 -> Herb
  b3 -> Homer

  p1 [shape=circle,label="",height=0.01,width=0.01];
  q1 [shape=circle,label="",height=0.01,width=0.01];
  q2 [shape=circle,label="",height=0.01,width=0.01];
  q3 [shape=circle,label="",height=0.01,width=0.01];
  {rank=same; Homer -> p1 -> Marge};
  {rank=same; q1 -> q2 -> q3};
  {rank=same; Bart; Lisa; Maggie};
  p1 -> q2;
  q1 -> Bart;
  q2 -> Lisa;
  q3 -> Maggie;

  x1 [shape=circle,label="",height=0.01,width=0.01];
  y1 [shape=circle,label="",height=0.01,width=0.01];
  y2 [shape=circle,label="",height=0.01,width=0.01];
  y3 [shape=circle,label="",height=0.01,width=0.01];
  {rank=same; Clancy -> x1 -> Jackeline};
  {rank=same; y1 -> y2 -> y3};
  {rank=same; Marge; Patty; Selma};
  {rank=same; Bart; Ling}
  x1 -> y2;
  y1 -> Marge;
  y2 -> Patty;
  y3 -> Selma;
  Selma -> Ling;
}

now produces this:

So, looks good except for that strange edge around Homer.If I could find a way to move Abraham, Mona and Herb to the left hand side of the picture then I would have a perfectly aligned picture.

Any ideas on how to achieve that?

Answer 3

Here is an other solution :

digraph simpsons {  
  subgraph Generation0 {
    rank = same
    Abraham [shape = box, color = blue]
    Mona [shape = box, color = pink]
    AbrahamAndMona [shape = point]
    Abraham -> AbrahamAndMona [dir = none]
    AbrahamAndMona -> Mona [dir = none]

    Clancy [shape = box, color = blue]
    Jackeline [shape = box, color = pink]
    ClancyAndJackeline [shape = point]
    Clancy -> ClancyAndJackeline [dir = none]
    ClancyAndJackeline -> Jackeline [dir = none]
  }

  subgraph Generation0Sons {
    rank = same
    AbrahamAndMonaSons [shape = point]
    HerbSon [shape = point]
    HomerSon [shape = point]
    HerbSon -> AbrahamAndMonaSons [dir = none]
    HomerSon -> AbrahamAndMonaSons [dir = none]

    MargeSon [shape = point]
    PattySon [shape = point]
    SelmaSon [shape = point]
    MargeSon -> PattySon [dir = none] 
    PattySon -> SelmaSon [dir = none] 
  }

  AbrahamAndMona -> AbrahamAndMonaSons [dir = none]
  ClancyAndJackeline -> PattySon [dir = none]

  subgraph Generation1 {
    rank  =  same
    Herb [shape = box, color = blue] 
    Homer [shape = box, color = blue] 
    Marge [shape = box, color = pink] 
    Patty [shape = box, color = pink] 
    Selma [shape = box, color = pink] 

    HomerAndMarge [shape = point]
    Homer -> HomerAndMarge [dir = none]
    Marge -> HomerAndMarge [dir = none]
  }

  HerbSon -> Herb [dir = none]
  HomerSon -> Homer [dir = none]
  MargeSon -> Marge [dir = none]
  PattySon -> Patty [dir = none]
  SelmaSon -> Selma [dir = none]

  subgraph Generation1Sons {
    rank  =  same
    BartSon [shape = point] 
    LisaSon [shape = point] 
    MaggieSon [shape = point] 

    BartSon -> LisaSon [dir = none]
    LisaSon -> MaggieSon [dir = none]
  }

  HomerAndMarge -> LisaSon [dir = none]

  subgraph Generation2 {
    rank  =  same
    Bart [shape = box, color = blue] 
    Lisa [shape = box, color = pink] 
    Maggie [shape = box, color = pink] 
    Ling [shape = box, color = blue] 
  }

  Selma -> Ling [dir = none]
  BartSon -> Bart [dir = none]
  LisaSon -> Lisa [dir = none]
  MaggieSon -> Maggie [dir = none]
}

And the result : http://dl.dropbox.com/u/72629/simpsons.png

Answer 4

Gramps (www.gramps-project.org) generates dot files for family trees, with or without marriage nodes. There is also a way to see this in the Gramps interface itself. http://gramps-project.org/wiki/index.php?title=Graph_View So I would say, look at the output of your family tree as created by Gramps