how to use circle pack layout in ggraph library in r

Question

what data format is necessary to create ggraph circlepack layout? It seems to require a hierarchy.

I tried normally vertices and nodes, which apparently doesn't work.

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()

I then tried a dendrogram object which doesn't work either. If i want to show several groups with sub-items in packed circle, how shall i build the graph object?

the data frame is more like this

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

that's what i'm trying to figure out. for the df in the last row, how can i make it into a graph object that accepts the circle layout? thanks. — santoku, May 02 '17 at 15:14

yeedle · Accepted Answer · 2017-05-03T14:06:32.367

1

A circlepack layout models a hierarchical/tree-like structure with one root and no cycles. To model your df as a circlepack layout, you have to consider that a and b in the group column are both roots. If we add a root to the df, and have both a and b be children of that root, we can visualize it as a 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()

edited May 03 '17 at 14:06

answered May 02 '17 at 16:05

yeedle

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thanks @yeedle. how can i pass 'size' or color to the small circle? – santoku May 03 '17 at 12:54
Is size an attribute of the nodes or the edges? – yeedle May 03 '17 at 12:55
the node (subitems) – santoku May 03 '17 at 12:56
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You have to set it as an attribute of the graph object. I'll update my answer to add this – yeedle May 03 '17 at 13:59
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if you want to use `size` instead of `depth` as the fill color, just use `aes(fill = size)` instead of `aes(fill = depth)` in `geom_node_circle` – yeedle May 03 '17 at 14:09
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protip: if you want to know what data `ggraph` uses to create the visualization, check the dataframe that`ggraph::create_layout(graph, 'circlepack', weight = 'size')` outputs. – yeedle May 03 '17 at 14:11
I had to remove the quotes around size from ggraph(graph, layout = "circlepack", weight = 'size') + – Shamsa Jan 02 '20 at 06:33

how to use circle pack layout in ggraph library in r

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