Preventing graphviz from rearranging nodes

Question

I am trying to visualize a tree structure using graphviz, problem is as the graph gets bigger graphviz starts to rearrange the order of the nodes. Say I have the following,

  A
/ | \
B C D

it becomes,

  A
/ | \
B D C

it probably does this to save space but in my context order of the nodes matter I have tried adding,

graph [ordering="out"];

but it did not change the output.

EDIT:

digraph bt {
graph [ordering="out"];
node [style="rounded", shape=box]
N_2386 -> N_2387
N_2387 -> N_2388
N_2388 -> N_2389
N_2388 -> N_2390
N_2387 -> N_2391
N_2386 -> N_2392
subgraph cluster_2393 {
labeljust = "l";
style=dashed;color="#B0B0B0"
N_2392 -> N_2394
N_2394 -> N_2395
N_2395 -> N_2396
N_2396 -> N_2397
N_2397 -> N_2398
N_2397 -> N_2399
N_2396 -> N_2400
N_2400 -> N_2401
N_2400 -> N_2402
N_2395 -> N_2403
N_2403 -> N_2404
N_2404 -> N_2405
N_2405 -> N_2406
N_2403 -> N_2407
N_2407 -> N_2408
N_2408 -> N_2409
N_2409 -> N_2410
N_2410 -> N_2411
N_2411 -> N_2412
N_2412 -> N_2413
N_2412 -> N_2414
N_2412 -> N_2415
N_2411 -> N_2416
N_2416 -> N_2417
N_2416 -> N_2418
N_2416 -> N_2419
N_2408 -> N_2420
N_2408 -> N_2421
N_2403 -> N_2422
N_2395 -> N_2423
N_2392 -> N_2424
}
}

graph in question What I need is, N_2387 should be on the right N_2392 should be on the left. Which is the order I insert them.

Answer 1

If you change the first branch to a subgraph the two subgraphs will be ordered as written in the file.

It seems that the subgraph as a higher precedence as a normal node and therefor the ordering=out seems not to be honored.

This works:

digraph bt {
  graph [ordering="out"];
  node [style="rounded", shape=box]
  N_2386 -> N_2387
  subgraph cluster_first {
    N_2387 -> N_2388
    N_2388 -> N_2389
    N_2388 -> N_2390
    N_2387 -> N_2391
  }
  N_2386 -> N_2392
  subgraph cluster_2393 {
    labeljust = "l";
    style=dashed;color="#B0B0B0"
    N_2392 -> N_2394
    N_2394 -> N_2395
    N_2395 -> N_2396
    N_2396 -> N_2397
    N_2397 -> N_2398
    N_2397 -> N_2399
    N_2396 -> N_2400
    N_2400 -> N_2401
    N_2400 -> N_2402
    N_2395 -> N_2403
    N_2403 -> N_2404
    N_2404 -> N_2405
    N_2405 -> N_2406
    N_2403 -> N_2407
    N_2407 -> N_2408
    N_2408 -> N_2409
    N_2409 -> N_2410
    N_2410 -> N_2411
    N_2411 -> N_2412
    N_2412 -> N_2413
    N_2412 -> N_2414
    N_2412 -> N_2415
    N_2411 -> N_2416
    N_2416 -> N_2417
    N_2416 -> N_2418
    N_2416 -> N_2419
    N_2408 -> N_2420
    N_2408 -> N_2421
    N_2403 -> N_2422
    N_2395 -> N_2423
    N_2392 -> N_2424
  }
}

Answer 2

If you want to control ordering of specific items use an invisible edge between them. Combining this with the rank directive gives you a lot of control.

eg: here's a sample tagcloud layout from Graphviz:

/*
Using a graph and relationships just to push things onto different lines.
Two layout rules:
1) all items on a given line go into a "rank=same" phrase 
2) a relationship is needed between the first word on each line and the next line down to
   force the vertical alignment.
*/
digraph {
    edge[style=invisible]
    node[shape=none]

    fred [fontsize=18]
    harry [fontsize=8]
    jack [fontsize=12]
    sally [fontsize=12]
    mika
    amy
    jan
    jack -> fred
    fred -> mika
    {rank=same;fred;harry}
    {rank=same;mika amy; jan}
}