如何在 DiagrammeR for R 中使用 GraphViz 图

Question

我正在尝试在 DiagrammeR 中使用 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)

给出：

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

有什么方法可以将 GraphViz 图转换或输入到 DiagrammeR 环境中吗？

Answer 1

grViz 采用描述图形的字符串（vis.js 样式）：它由 vis.js 解释。它的 return 值是一个 htmlwidget 对象。

render_graph 接受一个 dgr_graph 对象，使用 create_graph 函数创建。

可以看到in the DiagrammeR doc

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：来自下面提到的文档："If you'd like to return the Graphviz DOT code (to, perhaps, share it or use it directly with the Graphviz command-line utility), just use output = "DOT" in the render_graph()"

所以

您可以使用 create_graph 生成 graphviz 点代码
您可以在 DiagrammeR 中直接使用 grViz 的 graphviz 点代码

Answer 2

这里的问题是 ~~render_graph(myGraph)~~，仅使用 myGraph 就很有魅力。

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)~~ Does not work in R.

只需 myGraph 即可。

如何在 DiagrammeR for R 中使用 GraphViz 图

How to use GraphViz graphs in DiagrammeR for R

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