Extract the shift matrix from a SimInf_model object

Get the shift matrix events@N that determines how individuals are shifted between compartments when processing enter, internal transfer and external transfer events. Each row in the shift matrix corresponds to one compartment in the model, and each column defines a transfer pattern. The shift value of an event selects which column to use, and the value \(N[p, q]\) indicates how many compartments to move (or place, for enter events) individuals from compartment \(p\). See SimInf_events for details on the event processing.

Usage

shift_matrix(model)

# S4 method for class 'SimInf_model'
shift_matrix(model)

Arguments

model

The SimInf_model object to extract the shift matrix from.

Value

The integer shift matrix events@N where each row corresponds to one compartment in the model.

See also

shift_matrix<- to set the shift matrix, and select_matrix to extract the select matrix. The vignette "Scheduled events" for a tutorial on scheduled events, see vignette("Scheduled events", package = "SimInf").

Examples

## Create an 'SIR' model.
model <- SIR(
  u0 = data.frame(
    S = 100,
    I = 10,
    R = 0),
  tspan = 1:5,
  beta = 0.16,
  gamma = 0.077
)

## Extract the shift matrix from the model.
shift_matrix(model)
#> <0 x 0 matrix>

## Change the shift matrix so that susceptible individuals are
## moved to the 'R' compartment (compartment 1 + 2 = 3) when
## processing an event with 'shift' = 1.
shift_matrix(model) <- data.frame(
  compartment = "S",
  shift = 1,
  value = 2
)

## Extract the updated shift matrix from the model.
shift_matrix(model)
#>   1
#> S 2
#> I 0
#> R 0