R ggraph: Decrease distance between nodes

Question

I'm creating a sample ego network plot, but I'd like the nodes to be closer together, specifically, the alter nodes closer to the ego node. My code:

library(tidyverse)
library(igraph)
library(gridExtra)
library(ggraph)
library(tidygraph)
library(ggplot2)
library(graphlayouts)

edges <- read.table(text = 
"ego    wave    fid1        fid2        fid3        fid4        fid5
 Ego    1       Friend_A    Friend_B    Friend_C    NA        Friend_D
 Ego    2       Friend_E    Friend_F    NA        NA          Friend_G
 Ego    3       Friend_H    NA        Friend_I  Friend_G    Friend_J
 Ego    4       Friend_H    NA        NA        NA        NA
 Ego    5       Friend_K    NA        NA          NA          Friend_F", header = TRUE) %>%

  mutate_all(function(x) gsub("_"," ",x)) %>%
  pivot_longer(.,
               cols = c(fid1:fid5)) %>%
  select(., ego, alter = value, wave) %>% na.omit()

ego <-   as.data.frame(edges$ego) %>%
         rename("id" = "edges$ego")
alter <- as.data.frame(edges$alter) %>%
         rename("id" = "edges$alter")

nodes <- bind_rows(ego, alter) %>% distinct() %>%
         mutate(label = case_when(id == "Ego" ~ 1,
                                  TRUE ~ 0))

g1 <- graph_from_data_frame(d = filter(edges, wave == 1), vertices = nodes, directed = TRUE) %>%
      delete.vertices(., which(degree(.)==0))

as_tbl_graph(g1) %>%
      create_layout(., layout = 'kk') %>%
      ggraph(.) + 
      geom_edge_link(color = "grey", 
                     arrow = arrow(type = "closed",
                                   angle = 25,
                                   length = unit(1.5, 'mm')), 
                     end_cap = circle(3.5, 'mm'), 
                     width = 0.5, show.legend = FALSE) +        
      geom_node_point(aes(fill = factor(label)), , shape = 21, size = 7, color = "black") +
      scale_fill_hue(l=40) +
      geom_node_text(aes(label = name), vjust = -1.5, hjust = 0.5) +
      theme_graph()+
      theme(legend.position = "none")+
      labs(title = "Wave 1")

Output:

Given how small the ego network is, I'd like the alters nodes to be closer to ego. Is there a way to shorten the distance between the nodes?

Answer 1

I was able to shorten the distance by changing the x and y axis limits:

as_tbl_graph(g1) %>%
  create_layout(., layout = 'kk') %>%
  ggraph(.) + 
  geom_edge_link(color = "grey", 
                 arrow = arrow(type = "closed",
                               angle = 25,
                               length = unit(1.5, 'mm')), 
                 end_cap = circle(3.5, 'mm'), 
                 width = 0.5, show.legend = FALSE) +        
  geom_node_point(aes(fill = factor(label)), , shape = 21, size = 7, color = "black") +
  scale_fill_hue(l=40) +
  geom_node_text(aes(label = name), vjust = -1.5, hjust = 0.5) +
  ylim(-3, 3) +
  xlim(-3, 3) +
  theme_graph()+
  theme(legend.position = "none")+
  labs(title = "Wave 1")