example of how to define graph in DiagrammeR for graphviz

code.R

library(DiagrammeR)


mat <-  structure(
  c(0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 
    0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 1, 
    0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 
    0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 
    1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 
    0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 
    0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 
    0)
  , .Dim = c(12L, 12L)
  , .Dimnames = list(
      c("A", "B", "C", "D",
        "E", "F", "G", "H", "I", "J", "K", "L")
      , c("A", "B", "C", "D",
          "E", "F", "G", "H", "I", "J", "K", "L"))
)

temp <- dplyr::filter(
  reshape2::melt(mat)
  ,value==1
)

#not the best way, but a way
#  let's assume we have a source/target and ignore our prev matrix
#  so we could use any edgelist
grViz(sprintf(
  sociogram <- "
digraph boxes_and_circles {

  # several 'node' statements
  node [shape = circle, fixedsize = true, width = 0.9, color = blue] // sets as circles
  %s
  
  # several 'edge' statements
  edge [color = red] // this sets all edges to be red 
  %s
  
  # a 'graph' statement
  graph [overlap = true, fontsize = 20]
}"
  # get our nodes
  ,paste0(unique(as.vector(sapply(temp[,1:2],as.character))),collapse=";")
  # get our edges
  ,paste(temp[,1],temp[,2],sep="->",collapse=";")
), engine = "circo")



# just for fun

# as a check let's use Rgraphviz
library(Rgraphviz)
plot(graphAM(mat,"directed"),"circo")

# no formatting but a way to go from Rgraphviz/graph to DiagrammeR
tf = tempfile()
toDot( graphAM(mat,"directed"), tf )
grViz( tf, engine = "circo" )

As a non-expert at using sprintf, I'm just trying to work out how this works. Does the use of new lines of '%s' after the 'node' and 'edge' definitions essentially tell it to input a character string. Then the character strings are defined in order afterwards?

sprintf is nice in that is has been defined across multiple languages. %s means a string. There are other % types also. By default, the arguments fill in the %s in order. The key change in your example was the collapse = ";" argument in paste.

Awesome - thanks muchly, this is terrific!

@jalapic @timelyportfolio to continue with your learning (and if you haven't already located it), I posted a link to the Graphviz DOT manual on the DiagrammeR README. Lots of great information there.