OutDegree-methods: `OutDegree`

Description

The number of herds with direct movements of animals from the root herd during the defined time window used for tracing

Arguments

a ContactTrace object, or a list of ContactTrace objects or a data.frame with movements of animals between holdings, see Trace for details.

root

vector of roots to calculate outdegree for.

tEnd

the last date to include outgoing movements. Defaults to NULL

days

the number of previous days before tEnd to include outgoing movements. Defaults to NULL

outBegin

the first date to include outgoing movements. Defaults to NULL

outEnd

the last date to include outgoing movements. Defaults to NULL

Value

A data.frame with the following columns: [object Object],[object Object],[object Object],[object Object],[object Object]

Details

The time period used for OutDegree can either be specified using tEnd and days or outBegin and outEnd.

If using tEnd and days, the time period for outgoing contacts ends at tEnd and starts at days prior to tEnd. The outdegree will be calculated for each combination of root, tEnd and days.

An alternative way is to use outBegin and outEnd. The time period for outgoing contacts starts at outBegin and ends at outEndDate. The vectors root outBegin, outEnd must have the same lengths and the outdegree will be calculated for each index of them.

The movements in OutDegree is a data.frame with the following columns: [object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

References

Dube, C., et al., A review of network analysis terminology and its application to foot-and-mouth disease modelling and policy development. Transbound Emerg Dis 56 (2009) 73-85, doi: 10.1111/j.1865-1682.2008.01064.x
Noremark, M., et al., Network analysis of cattle and pig movements in Sweden: Measures relevant for disease control and riskbased surveillance. Preventive Veterinary Medicine 99 (2011) 78-90, doi: 10.1016/j.prevetmed.2010.12.009

Examples

Run this code

## Load data
data(transfers)

## Perform contact tracing using tEnd and days
contactTrace <- Trace(movements=transfers,
                      root=2645,
                      tEnd='2005-10-31',
                      days=91)

## Calculate outdegree from a ContactTrace object
od.1 <- OutDegree(contactTrace)

## Calculate outdegree using tEnd and days
od.2 <- OutDegree(transfers,
                  root=2645,
                  tEnd='2005-10-31',
                  days=91)

## Check that the result is identical
identical(od.1, od.2)

## Calculate outdegree for all included herds
## First extract all source and destination from the dataset
root <- sort(unique(c(transfers$source,
                      transfers$destination)))

## Calculate outdegree
result <- OutDegree(transfers,
                    root=root,
                    tEnd='2005-10-31',
                    days=91)