inertia {remstats}

inertia

Description

Specifies the statistic for an inertia effect in the tie-oriented model or the receiver choice step of the actor-oriented model.

Usage

inertia(scaling = c("none", "prop", "std"), consider_type = TRUE)

Arguments

scaling

the method for scaling the inertia statistic. Default is to not scale the statistic (scaling = "none"). Alternatively, the statistics can be scaled by specifying 'prop', in which raw counts are divided by the outdegree of the sender at time t (see 'details') or standardization of the raw counts per time point can be requested with 'std'.

consider_type

logical, indicates whether to count the number of past events separately for each event type (TRUE, default) or sum across different event types (FALSE).

Details

An inertia effect refers to the tendency for dyads to repeatedly interact with each other (tie-oriented model) or for actors to repeatedly choose the same actor as receiver of their events (actor-oriented model). The statistic at timepoint t for dyad (i,j) resp. receiver j is equal to the number of (i,j) events before timepoint t.

Optionally, a scaling method can be set with scaling. By scaling the inertia count by the outdegree of the sender ("prop"), the statistic refers to the fraction of messages send by actor i that were send to actor j. If actor i hasn't send any messages yet it can be assumed that every actor is equally likely to receive a message from i and the statistic is set equal to 1/(n-1), where n refers to the number of actors. The resulting statistic is similar to the "FrPSndSnd" statistic in the R package 'relevent', or the persistence statistic in Section 2.2.2 of Butts (2008). Note that this scaling method is only defined for directed events.

Value

List with all information required by 'remstats::remstats()' to compute the statistic.

Examples

reh_tie <- remify::remify(history, model = "tie")
effects <- ~ inertia()
remstats(reh = reh_tie, tie_effects = effects)

reh_actor <- remify::remify(history, model = "actor")
remstats(reh = reh_actor, receiver_effects = effects)