get_attr_at: Get Tracked Attributes at a Given Time Step

In EpiModel: Mathematical Modeling of Infectious Disease Dynamics

Get Tracked Attributes at a Given Time Step

Description

Reconstructs the state of all tracked attributes at a specific time step from the delta-compressed attribute history. Returns a tibble with one row per active node and one column per tracked attribute.

Usage

get_attr_at(sim, at, sim_num = 1, compute_age = FALSE)

Arguments

sim	An EpiModel object of class netsim.
at	The time step at which to reconstruct attributes, on the time step labels of sim (see truncate_sim()). It must lie between the start of the attribute history and the last time step. The history starts at the first time step for a new simulation, and at start - 1 for a restarted one, whose history starts again from a full snapshot of the state it restarted from.
sim_num	The simulation number to use (default 1).
compute_age	If TRUE and age is tracked, compute the age of nodes at at from their last recorded age, assuming age in years and 364 days in a year. This needs a time.unit parameter (the number of days in a time step) in sim$param, passed to param.net or set by the initialization module (as EpiModelHIV does from its epistats).

Value

A tibble with columns unique_id, active, and one column per tracked attribute, containing the most recent value at or before at for each active node.

See Also

record_attr_history(), get_attr_history()

Examples

nw <- network_initialize(n = 100)
est <- netest(nw, formation = ~edges, target.stats = 50,
              coef.diss = dissolution_coefs(~offset(edges), 10),
              verbose = FALSE)
control <- control.net(type = "SI", nsteps = 20, nsims = 1,
                       tracked.attributes = "status", verbose = FALSE)
sim <- netsim(est, param.net(inf.prob = 0.3, act.rate = 1),
              init.net(i.num = 10), control)

# The status of every node at time step 10
at10 <- get_attr_at(sim, at = 10)
head(at10)
table(at10$status)

EpiModel documentation built on Oct. 16, 2026, 5:07 p.m.