如何在R的DiagrammeR中使用GraphViz图

Question

我正在DiagrammeR中尝试使用GraphViz图。我该怎么做？

myGraph = grViz("
digraph boxes_and_circles {
  # a 'graph' statement
  graph [overlap = true, fontsize = 10]
  # several 'node' statements
  node [shape = box,
        fontname = Helvetica]
  A; B; C; D; E; F
  node [shape = circle,
        fixedsize = true,
        width = 0.9] // sets as circles
  1; 2; 3; 4; 5; 6; 7; 8
  # several 'edge' statements
  A->1 B->2 B->3 B->4 C->A
  1->D E->A 2->4 1->5 1->F
  E->6 4->6 5->7 6->7 3->8
}
")

然后我想在DiagrammeR中使用它，但它不允许。

render_graph(myGraph)

提供：

Error: class(graph) == "dgr_graph" are not all TRUE

有没有一种方法可以将GraphViz图转换或输入到DiagrammeR环境中？

Answer 1

grViz获取一个描述图形的字符串(vis.js样式(：它由vis.js解释。它的返回值是一个htmlwidget对象。

render_graph获取使用create_graph函数创建的dgr_graph对象。

你可以在DiagrammeR文档中看到

library(DiagrammeR)
# Create a simple NDF
nodes <-
  create_nodes(
    nodes = 1:4,
    type = "number")
# Create a simple EDF
edges <-
  create_edges(
    from = c(1, 1, 3, 1),
    to = c(2, 3, 4, 4),
    rel = "related")
# Create the graph object,
# incorporating the NDF and
# the EDF, and, providing
# some global attributes
graph <-
  create_graph(
    nodes_df = nodes,
    edges_df = edges,
    graph_attrs = "layout = neato",
    node_attrs = "fontname = Helvetica",
    edge_attrs = "color = gray20")
# View the graph
render_graph(graph)

DiagrammeR可以生成Graphviz代码：从下面提到的文档："如果你想返回GraphvizDOT代码(也许是为了共享它或直接与Graphvi兹命令行实用程序使用它(，只需在render_graph((中使用output="DOT"即可。">

所以

1. 您可以使用creategraph生成graphviz点代码
2. 您可以在DiagrammeR中将graphviz点代码直接与grViz一起使用

Answer 2

这里的问题是render_graph(myGraph)，只使用myGraph就像魅力一样。

library(DiagrammeR)
myGraph = grViz("
digraph boxes_and_circles {
  # a 'graph' statement
  graph [overlap = true, fontsize = 10]
  # several 'node' statements
  node [shape = box,
        fontname = Helvetica]
  A; B; C; D; E; F
  node [shape = circle,
        fixedsize = true,
        width = 0.9] // sets as circles
  1; 2; 3; 4; 5; 6; 7; 8
  # several 'edge' statements
  A->1 B->2 B->3 B->4 C->A
  1->D E->A 2->4 1->5 1->F
  E->6 4->6 5->7 6->7 3->8
}
") 
myGraph

render_graph(myGraph(在R.中不起作用

只有myGraph可以正常工作。