duration: Compute Observed Activity Durations or Event Counts for Edges or Vertices

Description

Computes observed activity durations or event counts for edges or vertices, aggregating at the edges, spell, or dyads level.

Usage

edgeDuration(nd, mode = c("duration", "counts"), subject = c("edges", "spells", "dyads"),
          e = seq_along(nd$mel), start = NULL, end = NULL, active.default = TRUE)
          
vertexDuration(nd, mode = c("duration", "counts"), subject = c("vertices", "spells"),
     v = seq_len(network.size(nd)), active.default = TRUE)

Arguments

networkDynamic object to be evaluated

mode

option determining if the 'duration' of the spells should be summed, or simply the 'counts' of the number of spells. The later option is useful when the network contains events of zero duration.

subject

option describing the unit of analysis that the durations or counts should be aggregated at. 'spells' considers each event independently. For tVertexDuration, 'vertices' sums all the spells corresponding to a single

numeric vector of edge ids to consider.

numeric vector of vertex ids to consider.

start

optional numeric value to be used to censor onset times. (not yet supported for vertices, must use net.obs.period instead.)

end

optional numeric value to be used to censor terminus times. (not yet supported for vertices, must use net.obs.period instead.)

active.default

logial, should edges or vertices with no timing information be considered always active by default?

Value

A vector of values corresponding to the selected subjects with the count or duration of events. If the network contains no edges/vertices, numeric(0) will be returned.

Details

The function sums the durations of edge or vertex events or,in order to provide a useful metric for networks having zero-duration events, simply counts them. It is implemented by wrapping a call to as.data.frame.networkDynamic or get.vertex.activity. In many cases the output of the function will be fed to another statistical summary function like summary or hist. The level of aggregation can be selected by setting the subject to either spells, edges, or dyads. Note that the 'observed' durations may not match the 'true' (statistically estimated) durations for a network due to the censoring of edges/vertices.

Examples

Run this code

# look at the distributions of edge durations for
# a real-world contact network
require(networkDynamicData)
data(hospital_contact)
summary(edgeDuration(hospital,subject='edges'))
summary(edgeDuration(hospital,mode='counts',subject='edges'))
# look at the vertex durations for a network were 
# vertices are not present every day
require(networkDynamic)
data(windsurfers)
vertexDuration(windsurfers)