GERGM (version 0.6.2)

simulate_networks: A Function to simulate networks from a GERGM with given theta parameters.

Description

Simulates networks from a GERGM for a given set of parameter values.

Usage

simulate_networks(formula, mutual = 0, ttriads = 0, ctriads = 0,
  in2stars = 0, out2stars = 0, twostars = 0,
  simulation_method = c("Metropolis", "Gibbs"),
  network_is_directed = c(TRUE, FALSE),
  number_of_networks_to_simulate = 500, thin = 1, proposal_variance = 0.1,
  downweight_statistics_together = TRUE, MCMC_burnin = 100, seed = 123,
  omit_intercept_term = FALSE, ...)

Arguments

formula

A formula object that specifies which statistics the user would like to include while simulating the network, and the network the user is providing as the initial network. Currently, the following statistics can be specified: c("out2stars", "in2stars",

mutual

The theta value provided for the reciprocity parameter, defaults to 0. Only statistics for structural terms included in formula will be used.

ttriads

The theta value provided for the transitive triads parameter, defaults to 0. Only statistics for structural terms included in formula will be used.

ctriads

The theta value provided for the cyclic triads parameter, defaults to 0. Only statistics for structural terms included in formula will be used.

in2stars

The theta value provided for the in 2-stars parameter, defaults to 0. Only statistics for structural terms included in formula will be used.

out2stars

The theta value provided for the out 2-starts parameter, defaults to 0. Only statistics for structural terms included in formula will be used.

twostars

The theta value provided for the undirected 2-starts parameter, defaults to 0. Only statistics for structural terms included in formula will be used.

simulation_method

Default is "Metropolis" which allows for exponential downweighting, can also be "Gibbs".

network_is_directed

Logical specifying whether or not the observed network is directed. Default is TRUE.

number_of_networks_to_simulate

Number of simulations generated for estimation via MCMC. Default is 500.

thin

The proportion of samples that are kept from each simulation. For example, thin = 1/200 will keep every 200th network in the overall simulated sample. Default is 1.

proposal_variance

The variance specified for the Metropolis Hastings simulation method. This parameter is inversely proportional to the average acceptance rate of the M-H sampler and should be adjusted so that the average acceptance rate is approximately 0.25. Default is 0

downweight_statistics_together

Logical specifying whether or not the weights should be applied inside or outside the sum. Default is TRUE and user should not select FALSE under normal circumstances.

MCMC_burnin

Number of samples from the MCMC simulation procedure that will be discarded before drawing the samples used for estimation. Default is 100.

seed

Seed used for reproducibility. Default is 123.

omit_intercept_term

Defualts to FALSE, can be set to TRUE if the user wishes to omit the model intercept term.

...

Optional arguments, currently unsupported.

Value

• A list object containing simulated networks and parameters used to specify the simulation. See the $MCMC_Output field for simulated networks.

Examples

set.seed(12345)
net <- matrix(runif(100),10,10)
diag(net) <- 0
colnames(net) <- rownames(net) <- letters[1:10]
formula <- net ~ ttriads + in2stars

test <- simulate_networks(formula,
 ttriads = 0.6,
 in2stars = -0.8,
 network_is_directed = TRUE,
 simulation_method = "Metropolis",
 number_of_networks_to_simulate = 100,
 thin = 1/10,
 proposal_variance = 0.5,
 downweight_statistics_together = TRUE,
 MCMC_burnin = 1000,
 seed = 456)