grow_NM {netcom}

Grow a Niche Model Network

Description

Grows an already existing network by adding a node according to the Niche Model mechanism. Nodes can only attach to previously grown nodes.

Usage

grow_NM(matrix, x, niches, connectance = 0.2, directed = TRUE, retcon = FALSE)

Arguments

matrix

Existing network to experience growth.

x

The ID of the node to be grown.

niches

Vector of length x, with values between zero and one corresponding to each node's niche.

connectance

Niche Model parameter specifying the expected connectivity of the network, which determines for a given node the niche space window within which it attaches to every other node. Defaults to 0.2.

directed

Binary variable determining if the network is directed, resulting in off-diagonal asymmetry in the adjacency matrix. Defaults to TRUE.

retcon

Binary variable determining if already existing nodes can attach to new nodes. Defaults to FALSE.

Details

Stirs a node in a Niche Model network.

Value

An adjacency matrix.

References

Williams, R. J., & Martinez, N. D. (2000). Simple rules yield complex food webs. Nature, 404(6774), 180-183.

Examples

# Import netcom
library(netcom)

size <- 10
existing_network <- matrix(sample(c(0,1), size = size^2, replace = TRUE), nrow = size, ncol = size)
new_network_prep <- matrix(0, nrow = size + 1, ncol = size + 1)
new_network_prep[1:size, 1:size] = existing_network
new_network <- grow_NM(matrix = new_network_prep, x = size + 1, niches = stats::runif(size))