如何在r中的ggraph库中使用circle pack布局

Question

创建ggraph circlepack布局需要什么数据格式？它似乎需要一个层次结构。

我通常尝试顶点和节点，这显然不起作用。

library(ggraph)
library(igraph)
edges=data.frame(from=c('a','b','c'), to= c('c','a','d'))
vertices=data.frame(nodes=c('a','b','c','d'), weight=c(1,2,3,4))
graph <- graph_from_data_frame(edges, vertices = vertices)
ggraph(graph, 'circlepack', weight = 'size') + 
geom_node_circle(size = 0.25, n = 50) + 
coord_fixed()

然后我尝试了一个树形图对象，它也不起作用。 如果我想在包装圆圈中显示多个包含子项目的组，我该如何构建图形对象？

数据框更像是

df <- data.frame(group=c("a","a","b","b","b"),    subitem=c("x","y","z,"u","v"), size=c(6,2,3,2,5))

Answer 1

circlepack布局模拟具有一个根且没有周期的分层/树状结构。要将df建模为circlepack布局，您必须考虑a列中的b和group都是根。如果我们在df中添加了一个根，并且a和b都是该根的子代，我们可以将其可视化为circlepack：

library(ggraph)
library(igraph)
library(dplyr)


df <- data.frame(group=c("root", "root", "a","a","b","b","b"),    
                 subitem=c("a", "b", "x","y","z","u","v"), 
                 size=c(0, 0, 6,2,3,2,5))

# create a dataframe with the vertices' attributes

vertices <- df %>% 
  distinct(subitem, size) %>% 
  add_row(subitem = "root", size = 0)

graph <- graph_from_data_frame(df, vertices = vertices)

ggraph(graph, layout = "circlepack", weight = 'size') + 
  geom_node_circle(aes(fill =depth)) +
# adding geom_text to see which circle is which node 
  geom_text(aes(x = x, y = y, label = paste(name, "size=", size))) +
  coord_fixed()