Brtdku

The first image is a hand drawn (using MS word) image of a graph. The second image is an attempt to generate the same graph using ggraph.

Following is the code I used to automatically draw the graph when given the node-edge connections (the code was adopted from this thread). I want to move the x and y axis of the ggraph as shown in the hand drawn graph (image 1). Reverse the x axis numbering from top to bottom and move the y axis to the top. How do I go about it?

library(igraph)

library(tidyverse)

library(ggraph)



V <- read.table(text = "x        y

                2 1

                4 2

                4 4

                2 5

                6 4

                3 7

                8 6", 

    header = T) %>%

  rownames_to_column("name")



E <- matrix(c(0,    1,    0,    0,    0, 0, 0,

              0,    0,    1,    0,    0, 0, 0,

              0,    0,    0,    1,    1, 0, 0,

              0,    0,    0,    0,    0, 1, 0,

              0,    0,    0,    0,    0, 0, 1,

              0,    0,    0,    1,    0, 0, 0,

              0,    0,    0,    0,    1, 0, 0), nrow = 7, byrow = T) %>%

  data.frame() %>% 

  rename_all(list(function(x) 1:7)) %>% 

  rownames_to_column(var = "from") %>% 

  gather(to, val, 2:6) %>% 

  filter(val == 1) %>%

  select(from, to)



g <- graph_from_data_frame(E, vertices = V, directed = F)



png("C:\Users\Yasoda\Downloads\rplot.png", width = 450, height = 450)



ggraph(g) + 

  geom_edge_link(edge_width = 1.3) + 

  geom_node_label(aes(label = name),label.r = unit(0.75, "lines"), 

                  label.size = 0.65, label.padding = unit(0.55,"lines"), show.legend = F) +

  ggtitle("My plot") +

  coord_flip() +

  expand_limits(x = 0, y = 0) +

  scale_x_continuous(expand = c(0, 0), limits = c(0, 9), breaks = c(0:9), minor_breaks = NULL) + 

  scale_y_continuous(expand = c(0, 0),limits = c(0, 9), breaks = c(0:9), minor_breaks = NULL) +

  theme_minimal() 





dev.off()

I tried using scale_x_reverse() but it distorts the layout and gives the warning "Scale for 'x' is already present.Adding another scale for 'x', which will replace the existing scale.". Also I tried the position = "top" option in the scale_y_continuous and it doesn't make a difference either.

ggraph(g) + 

  geom_edge_link(edge_width = 1.3) + 

  geom_node_label(aes(label = name),label.r = unit(0.75, "lines"), 

                  label.size = 0.65, label.padding = unit(0.55,"lines"), show.legend = F) +

  ggtitle("My plot") +

  coord_flip() +

  expand_limits(x = 0, y = 0) +



  # Using scale_x_reverse and swapping the limits

  scale_x_reverse(expand = c(0, 0), limits = c(9, 0), breaks = c(0:9), minor_breaks = NULL) + 

  # switching y position to "right" (pre-flip)

  scale_y_continuous(expand = c(0, 0),limits = c(0, 9), breaks = c(0:9), minor_breaks = NULL, position = "right") +

  theme_minimal()