causality: Examine The Causal Structure of Data

# #' @useDynLib causality causalityFruchtermanReingold
# export_tikz <- function(cgraph, file = stdout(), iterations = 10, height = 3,
#                                 width = 3)
# {
#   positions <- .Call("causalityFruchtermanReingold", graph = cgraph,
#                                                      nIterations = iterations,
#                                                      height = height,
#                                                      width = width)
#   positions <- round(positions, digits = 2)
#   edge_style <- function(edge) {
#     switch (edge,
#       "-->" = "directed",
#       "---" = "undirected",
#       "o->" = "circ-directed, uncertain",
#       "o-o" = "circ-circ, uncertain",
#       "++>" = "directed, certain",
#       "~~>" = "directed",
#       "<->" = "bidirected"
#     )
#   }
#   preamble <- c("\\documentclass[border = 3px]{standalone}\n",
#                 "\\usepackage{tikz}\n",
#                 "\\usetikzlibrary{shapes, arrows.meta}\n")
#   cat(preamble, file = file, sep = "")
#
#   cat("\\begin{document}\n", file = file, append = T)
#   cat("\\begin{tikzpicture}[{shorten >=1pt, >=stealth, scale = 1.5}]\n", file = file, append = T)
#
#   tikz.defs <- c("\\tikzstyle{node}          = [draw, fill = white, circle, scale =.75, line width = .7]\n",
#                  "\\tikzstyle{directed}      = [-{Latex[length = 2.5mm]}]\n",
#                  "\\tikzstyle{circ-directed} = [{Circle[open, length=2.5mm]}-{Latex[length = 3mm]}]\n",
#                  "\\tikzstyle{circ-circ}     = [{Circle[open, length = 2.5mm]}-{Circle[open, length = 2.5mm]}]\n",
#                  "\\tikzstyle{circ-circ}     = [{Circle[open, length = 2.5mm]}-{Circle[open, length = 2.5mm]}]\n",
#                  "\\tikzstyle{bidirected}    = [{Latex[length=3mm]}-{Latex[length=3mm]}]\n",
#                  "\\tikzstyle{certain}       = [green!85!black]\n",
#                  "\\tikzstyle{uncertain}     = [dashed, black]\n")
#
#   cat(tikz.defs, file = file, sep = "", append = T)
#   nodes <- cgraph$nodes
#   for (node in nodes) {
#       x <- positions[match(node, nodes), 1]
#       y <- positions[match(node, nodes), 2]
#       if (!is.null(cgraph$adjacencies[[node]]))
#         cat(sprintf("\\node[node] at (%f, %f) (%s) {%s};\n", x, y, node, node),
#                       file = file, append = T)
#
#   }
#
#   cat("\n", file = file, append = T)
#   edges <- cgraph$edges
#   for (i in 1:nrow(edges)) {
#       x    <- edges[i, 1]
#       y    <- edges[i, 2]
#       edge.type <- edge_style(edges[i, 3])
#       s <- sprintf("\\draw[%s, line width = 1] (%s) -- (%s);\n", edge.type, x, y)
#       cat(s, file = file, append = T)
#   }
#
#   cat("\n", file = file, append = T)
#   for (node in nodes) {
#       x <- positions[match(node, nodes), 1]
#       y <- positions[match(node, nodes), 2]
#       if (!is.null(cgraph$adjacencies[[node]]))
#         cat(sprintf("\\node[node] at (%f, %f) (%s) {%s};\n", x, y, node, node),
#                       file = file, append = T)
#
#   }
#   cat("\\end{tikzpicture}\n", file = file, append = T)
#   cat("\\end{document}\n", file = file, append = T)
#
# }