Simulate events based on specified formulas and coefficients

Usage

dem.simulate(
  events = matrix(0, 0, 4),
  formula_0_1 = NULL,
  formula_1_0 = NULL,
  coef_0_1 = numeric(0),
  coef_1_0 = numeric(0),
  coef_degree_0_1 = 0,
  coef_degree_1_0 = 0,
  n_events = 0,
  time = 0,
  max_events = 4e+05,
  n_nodes,
  verbose = FALSE,
  baseline_0_1 = NULL,
  baseline_1_0 = NULL,
  simultaneous_interactions = TRUE,
  seed = 123,
  directed = FALSE
)

Arguments

events: A matrix representing the initial events with columns time, from, to, and type (1 for start, 0 for end, 3 for exogenous changes). Defaults to an empty 4-column matrix.
formula_0_1: A one-sided formula specifying the sufficient statistics for the formation process (\(0 \rightarrow 1\)). The right-hand side must be composed of terms from redeem_terms. For example: ~ inertia() + degree. An intercept (~ 1) is the minimal specification. Defaults to NULL.
formula_1_0: A one-sided formula specifying the sufficient statistics for the dissolution process (\(1 \rightarrow 0\)). The right-hand side must be composed of terms from redeem_terms. An intercept (~ 1) is the minimal specification. Defaults to NULL.
coef_0_1: Numeric vector; coefficients for the formation process (\(0 \rightarrow 1\)). Defaults to an empty numeric vector.
coef_1_0: Numeric vector; coefficients for the dissolution process (\(1 \rightarrow 0\)). Defaults to an empty numeric vector.
coef_degree_0_1: Numeric; degree coefficient for the formation process (\(0 \rightarrow 1\)). Defaults to 0.
coef_degree_1_0: Numeric; degree coefficient for the dissolution process (\(1 \rightarrow 0\)). Defaults to 0.
n_events: Integer; number of events to simulate. Defaults to 0.
time: Numeric; simulation time limit. Defaults to 0.
max_events: Integer; maximum number of total events. Defaults to 400000.
n_nodes: Integer; the total number of actors in the network.
verbose: Logical; if TRUE, prints progress information. Defaults to FALSE.
baseline_0_1: Numeric vector; baseline for the 0 to 1 transition. If the formula for this process contains an Intercept or a degree term, then baseline_0_1 should be a numeric vector with length equal to the number of changepoints, representing the shifts in the baseline for each interval after the first. If the formula contains neither, then baseline_0_1 must have length equal to the number of changepoints + 1. Defaults to NULL.
baseline_1_0: Numeric vector; baseline for the 1 to 0 transition. Similar to baseline_0_1, its length depends on whether the 1 to 0 formula contains an intercept or degree term. Defaults to NULL.
simultaneous_interactions: Logical; whether to allow simultaneous interactions (i.e. multiple active events for the same actor or dyad at the same time). Defaults to TRUE.
seed: Integer; random seed for simulation. Defaults to 123.
directed: Logical; whether the interaction events are directed. Defaults to FALSE.

Value

A matrix of simulated events.

Note

Multi-stream event models are currently not supported in simulation.

Examples

# Simulate events from a DEM model structure
n <- 10
f_0_1 <- ~ 1 + inertia(transformation = "identity")
f_1_0 <- ~ 1

# Simulating events
evs <- dem.simulate(
  formula_0_1 = f_0_1,
  formula_1_0 = f_1_0,
  n_nodes = n,
  time = 2.0,
  coef_0_1 = c(1.0, 0.5),
  coef_1_0 = c(-0.5),
  seed = 42,
  max_events = 100
)
head(evs)
#>            [,1] [,2] [,3] [,4]
#> [1,] 0.02256350    5   10    1
#> [2,] 0.05274257    2    7    1
#> [3,] 0.06051135    5    9    1
#> [4,] 0.07809648    3    5    1
#> [5,] 0.07831044    1    7    1
#> [6,] 0.09898228    2    6    1