在 label 中将带有表情符号的图形保存为 pdf 在 R

Question

Using the top answer here:

How to export images of diagrammer in R

I managed to import a .dot file into R and and then export a visual plot of the graph containing names and arrows as a pdf using the lines

# setwd("/Folder with .dot graph file")

library(DiagrammeR)
library(DiagrammeRsvg)

DiagrammeR::grViz("mygraph.dot") %>%
  export_svg %>% charToRaw %>% rsvg_pdf("graph.pdf")

The label field in the .dot file contains emoji's representing countries. Here is a small portion of the .dot file below:

/* Created by igraph 1.2.6 */
digraph {
  0 [
    name=1
    type=NA
    label="A name\n🇺🇸"
    shape=note
    color=Black
    fillcolor=White
    style=filled
  ];
  1 [
    name=2
    type=NA
    label="Another Name\n🇺🇸"
    shape=note
    color=Black
    fillcolor=White
    style=filled
  ];
.
.
.
1 -> 0 [
    rel=a
    "type.x"=NA
    "type.y"=NA
  ];
2 -> 0 [
    rel=a
    "type.x"=NA
    "type.y"=NA
  ];
.
.
.
}

When I use the code above to convert the graph to a pdf, the emoji's do not appear in the final pdf.

Is there a way to convert a graph from a .dot file containing emoji's in the label into a pdf which will still display the emojis?

Answer 1

Using the comment by @charlie-gallagher , I was able to figure out a solution.

The first step is to export the full graph (with text labels, arrows, etc.) directly as an .svg .

svg = export_svg(grViz("mygraph.dot"))
write(svg, "mygraph.svg")

After the .svg file is created, I just used another application to convert the svg to a pdf.