makereduced: Run CONCOR and output reduced adjacency matrices

In ATraxLab/concorR: CONCOR and Supplemental Functions

Run CONCOR and output reduced adjacency matrices

Description

Takes a list of adjacency matrices, partitions using concor, and returns a list of reduced adjacency matrices and their corresponding cutoff densities. Each reduced matrix corresponds to one input relation. The sna package must be installed, but does not need to be attached.

Usage

make_reduced(adj_list, nsplit = 1, stat = 'density')

Arguments

adj_list	A list of adjacency matrices, each representing a different relation for the same nodes.
nsplit	The total number of splits CONCOR will (attempt to) perform.
stat	The statistic that will be used to determine if edges should be included in a reduced network. Default value is density

Details

A reduced network represents each identified position in the network as a single node. Links (or self-links) exist if the density (or normalized degree) of ties from that block to a target block is greater than a threshold density (or degree). In the default implementation, the density of the whole network is used as the threshold for each block. In the degree implementation, the normalized degree of the network is used as the threshhold.

In the list of input matrices adj_list, each should correspond to a different relation for the same nodes. Each adjacency matrix is partitioned with the CONCOR algorithm, continuing for nsplit divisions. After the threshold density is applied, each entry in the reduced matrix has values of 0 or 1.

Value

reduced_mat	A list of reduced matrices, one for each input matrix.
dens	A vector of the cut-off densities used (equal to the edge density of each entry in adj_list). Only for stat="density"
deg	A vector of the cut-off normalized degrees used (equal to the mean normalized degree of each entry in adj_list). Only for stat="degree".

References

S. Wasserman and K. Faust, Social Network Analysis: Methods and Applications (Cambridge University Press, 1994).

See Also

concor, make_blk

Examples

g1 <- matrix(c(0, 0, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0), ncol = 4)
rownames(g1) <- c("a", "b", "c", "d")
colnames(g1) <- c("a", "b", "c", "d")

g2 <- matrix(c(0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0), ncol = 4)
rownames(g2) <- c("a", "b", "c", "d")
colnames(g2) <- c("a", "b", "c", "d")

make_reduced(list(g1, g2), nsplit = 1)
make_reduced(list(g1, g2), nsplit = 1, stat="degree")

ATraxLab/concorR documentation built on June 28, 2023, 4:02 p.m.