CODEWITHSUNDEEP
rvisualizationdata-visualizationigraphvertices
Anastasia
Anastasia

Reputation: 105

Visualizing larger weights with thinner lines

I try to visualize data on cultural distances between countries with the use of networks in R. The distances are stored in matrices, e.g.:

          AT      BE     CH     CZ
AT    0       0.00276 0.148  0.109
BE    0.00276 0       0.145  0.112
CH    0.148   0.145   0      0.257
CZ    0.109   0.112   0.257  0

With the use of igraph package I get an image like:

map with cultural distance network

The code I use:

library(maps)
library(igraph)

df<-data.frame(from = c("at", "be", "ch", "cz"), to= c("be", "ch", "cz", "at"),
weight=c(0.003,0.145,0.257,0.109))
meta <- data.frame("name"=c("at", "be", "ch", "cz"),
"lon"=c(14.55,4.46,8.227,14.4738), "lat"=c(47.51,50.5,46.818,50.0755))

g <- graph.data.frame(df, directed=F, vertices=meta)
E(g)$color <- "brown"
# since weights are small, multiplying by 10
E(g)$width <- E(g)$weight*10
lo <- as.matrix(meta[,2:3])
map("world",  xlim = c(-8, 30),
ylim = c(35, 55), asp=1)
plot(g, layout=lo, add = TRUE, rescale = FALSE)

Now, the problem is that I want lines to be thin, if the corresponding weight is big. However, igraph does the opposite, and draws lines the thicker the bigger the weight is.

Is there any means to reverse this?

Upvotes: 2

Views: 95

Answers (1)

Julius Vainora
Julius Vainora

Reputation: 48211

Why not to define the width as inversely related to the weight in some way? For instance, using

E(g)$width <- 3 - E(g)$weight * 10

gives

enter image description here

You may experiment further and replace 3 and/or 10 with some other coefficients to achieve the desired result.

Upvotes: 1

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