使用 tidytext 将字数大小作为层添加到共现网络图表上的节点大小

Question

我有兴趣使用与 section 8.2.2 David Robinson and Julia Silge's Tidy Text mining book, such as this chart, except that I would like to have the sizes of the nodes change depending on how many times the term shows up in the data:

上所示类似的共现网络图表

上面的图表是用下面的代码建立的：

library(tidytext)
library(tidyverse)
library(widyr)
library(igraph)
library(ggraph)
library(jsonlite)

metadata <- fromJSON("https://data.nasa.gov/data.json")
nasa_keyword <- data_frame(id = metadata$dataset$`_id`$`$oid`, 
                           keyword = metadata$dataset$keyword) %>%
  unnest(keyword)

keyword_cors <- nasa_keyword %>% 
  group_by(keyword) %>%
  filter(n() >= 50) %>%
  pairwise_cor(keyword, id, sort = TRUE, upper = FALSE)

set.seed(1234)
keyword_cors %>%
  filter(correlation > .6) %>%
  graph_from_data_frame() %>%
  ggraph(layout = "fr") +
  geom_edge_link(aes(edge_alpha = correlation, edge_width = correlation), edge_colour = "royalblue") +
  geom_node_point(size = 5) +
  geom_node_text(aes(label = name), repel = TRUE,
                 point.padding = unit(0.2, "lines")) +
  theme_void()

我一直在研究 geom_node_point(aes(size = ??))，但我不知道如何配置代码来做到这一点。对我来说，部分问题是函数 graph_from_data_frame() 将数据框变成了一个看起来相当复杂的对象。

Answer 1

I would like to have the sizes of the nodes change depending on how many times the term shows up in the data

你可以

set.seed(1234)
keyword_cors %>%
  filter(correlation > .6) %>% 
  graph_from_data_frame(vertices = nasa_keyword %>% count(keyword) %>% filter(n >= 50)) %>% 
  ggraph(layout = "fr") +
  geom_edge_link(aes(edge_alpha = correlation, edge_width = correlation), 
                 edge_colour = "royalblue") +
  geom_node_point(aes(size = n)) + scale_size(range = c(1,10)) + 
  geom_node_text(aes(label = name), repel = TRUE,
                 point.padding = unit(0.2, "lines")) +
  theme_void()

这给你这样的东西：

vertices = nasa_keyword %>% count(keyword) %>% filter(n >= 50) 添加图的节点信息，更具体地说：节点 ID（第一个列）和出现次数 n（第二列）。
aes(size = n) 将此信息映射到节点大小。
scale_size(range = c(1,10)) 让我们定义最小值和最大磅值。

使用 tidytext 将字数大小作为层添加到共现网络图表上的节点大小

Adding word count size as a layer to the node size on a cooccurrence network chart using tidytext

r

tidytext

ggraph