Finds blocks of nodes with specified inter/intra group ties

signed_blockmodel_general(g, blockmat, alpha = 0.5)

## Arguments

g

igraph object with a sign edge attribute.

blockmat

Integer Matrix. Specifies the inter/intra group patterns of ties

alpha

see details

## Value

numeric vector of block assignments and the associated criterion value

## Details

The function minimizes P(C)=$$\alpha$$N+(1-$$\alpha$$)P, where N is the total number of negative ties within plus-sets and P be the total number of positive ties between plus-sets. This function implements the generalized model. For the structural balance version see signed_blockmodel.

David Schoch

## Examples

library(igraph)
# create a signed network with three groups and different inter/intra group ties
g1 <- g2 <- g3 <- graph.full(5)

V(g1)$name <- as.character(1:5) V(g2)$name <- as.character(6:10)
V(g3)$name <- as.character(11:15) g <- Reduce("%u%", list(g1, g2, g3)) E(g)$sign <- 1
E(g)$sign[1:10] <- -1 g <- add.edges(g, c(rbind(1:5, 6:10)), attr = list(sign = -1)) g <- add.edges(g, c(rbind(1:5, 11:15)), attr = list(sign = -1)) g <- add.edges(g, c(rbind(11:15, 6:10)), attr = list(sign = 1)) # specify the link patterns between groups blockmat <- matrix(c(1, -1, -1, -1, 1, 1, -1, 1, -1), 3, 3, byrow = TRUE) signed_blockmodel_general(g, blockmat, 0.5) #>$membership
#>   1 1 1 1 1 2 2 2 2 2 3 3 3 3 3
#>
#> \$criterion
#>  0
#>