Using DiagrammeR to place one rows of nodes below another

Question

Given the following flow chart derived via DiagrammeR package:

DiagrammeR::DiagrammeR(diagram =
                       "
                       graph LR;
                       A[Start]-->B;
                       B --> C;
                       C --> D;
                       D --> E;
                       E --> F;
                       ")

Would it be possible to wrap it so the node E is below node D and node F follows to the left as in the picture below:

Answer 1

You can do this using the graphviz option.

For example, you can get the basic node positions of the graph using

library(DiagrammeR)

grViz("
  digraph flow {
       D -> E;
       {rank=same ; A -> B -> C -> D};
       {rank=same ;           F -> E[dir=back]};
   }
")

And you can add a few attributes to prettify it

grViz('
  digraph flow {

       # set characteristics 
       node[shape=square, 
            height=1,
            color=skyblue, 
            penwidth=2,
            fillcolor=lavender, 
            style=filled,
            fontsize=25, 
            fontcolor=grey46,
            fontname = "helvetica" # this may be OS dependent
            ];
       edge[minlen=2, 
            color=grey,
            penwidth=2
            ];
       nodesep=0.5; #hack
       A[label=Start];

       # Graph
       D -> E;
       {rank=same ; A -> B -> C -> D};
       {rank=same ;           F -> E[dir=back]};
  }
')

Which produces