# Visualização de um grafo no R:

library(igraph)
g=read.graph("G1.net", format="pajek")
tkplot(g)
tkplot(g, vertex.size=30, vertex.color="lightblue", edge.color="red", vertex.label.font=2)

nomes=V(g)$id

tkplot(g, vertex.label=nomes, vertex.size=30, vertex.color="lightblue", edge.width=3, edge.color="red")


# Calcular a distribuição de Graus:

png(filename="G1_graus.png", height=500, width=500, bg="white")
library(igraph)
g = read.graph("G1.net",format="pajek")
d1 = degree.distribution(g, cumulative=FALSE)
len = length(d1)
par(mfrow=c(2,2))
barplot(d1, main="Distribuição de Graus",xlab="Graus", ylab="PDF", names.arg=c(0:(len-1)))
dev.off()
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# Calcular Medida de Centralidade (Closeness)

library(igraph)
g = read.graph("G1.net", format="Pajek")
cl = closeness(g)
cl

cl_max= max(cl)
cl_max

vindex_max = which(closeness(g) == cl_max)
vindex_max

vmax=V(g)[vindex_max]$id
vmax

cl_min= min(cl)
cl_min

vindex_min = which(closeness(g) == cl_min)
vindex_min

vmin=V(g)[vindex_min]$id
vmin
------------------------------------------------------------------------------------------------------
# Calcular Medida de Centralidade (Betweeness Vértices)

library(igraph)
g = read.graph("G1.net", format="Pajek")
b = betweenness(g)
b

bmax=max(b)
bmax

bindex_max = which(betweenness(g) == bmax)
bindex_max

bmax=V(g)[bindex_max]$id
bmax

bmin= min(b)
bmin

bindex_min = which(betweenness(g) == bmin)
bindex_min

bmin=V(g)[bindex_min]$id
bmin

------------------------------------------------------------------------------------------------------
# Calcular Medida de Centralidade (Betweenness Arestas)

vcount(g)
ecount(g)
E(g)

eb = edge.betweenness(g)
eb