Mapping a specific column of values to the scale color of vertexs in R

Question

Now I have a data frame df1:

v1                v2
a                 10
b                 1
c                 3
d                 7
.......

And another data frame df2:

v1                v2
d                 a
c                 a
b                 c
c                 d
...

I'd like to plot a network based on df2 with igraph:

plot(g, layout = layout_in_circle(g))

And the color of vertexes(a,b,c,d...) should be in range of red to blue and the bigger the value in v2, the color of that vertex should be more closer to red. I have tried:

require(igraph)
g = graph.data.frame(df)
plot(g, layout = layout_in_circle(g), vertex.color = color.scale(mention_counted$V2,c(0,1,1),c(1,1,0),0))

But the color of vertexes is not map to the value in v2 properly. Is there a way to do that? Thank you in advance!

Answer 1

library(igraph)
library(dplyr)

# data frame to get colours
dt1 = data.frame(v1 = c("a","b","c","d"),
                 v2 = c(10, 1, 3, 7))

dt1

#   v1 v2
# 1  a 10
# 2  b  1
# 3  c  3
# 4  d  7


# create color column
dt1$color = colorRampPalette(c("blue","red"))(max(dt1$v2))[dt1$v2]

dt1

#   v1 v2   color
# 1  a 10 #FF0000
# 2  b  1 #0000FF
# 3  c  3 #3800C6
# 4  d  7 #AA0055


# data frame to get network
dt2 = data.frame(v1 = c("d","c","b","c"),
                 v2 = c("a","a","c","d"))

dt2

#   v1 v2
# 1  d  a
# 2  c  a
# 3  b  c
# 4  c  d


# build graph
g = graph.data.frame(dt2)

# check order of vertices
V(g)

# + 4/4 vertices, named:
#   [1] d c b a


# get info for vertices in the right order
dt_info =
  data.frame(names = names(V(g))) %>%
  inner_join(dt1, by = c("names"="v1"))

dt_info

#   names v2   color
# 1     d  7 #AA0055
# 2     c  3 #3800C6
# 3     b  1 #0000FF
# 4     a 10 #FF0000

# plot graph
plot(g, vertex.color = dt_info$color)