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State and Flow Variable Names

Source: R/flow_frame.R
mp_vars.Rd

Get the state and/or flow variables in a model specification.

Usage

mp_state_vars(spec, topological_sort = FALSE, loops = "^$", trans = "")

mp_flow_vars(spec, topological_sort = FALSE, loops = "^$", trans = "")

mp_state_flow_vars(spec, topological_sort = FALSE, loops = "^$", trans = "")

Arguments

spec

Model specification (mp_tmb_model_spec).

topological_sort

Should the states and flows be topologically sorted to respect the main direction of flow? The default is no topological sorting, which differs from mp_flow_frame.

loops

Pattern for matching the names of flows that make the flow model not a DAG, which is a critical assumption when topologically sorting the order of states and flows in the output. This is only relevant if topological_sort is used.

trans

Add a prefix to the names for indicating if a transformed version of the variables is preferred.

Value

Character vector of names of all state and/or flow variables that have been explicitly represented in the model using functions like mp_per_capita_flow.

Functions

  • mp_state_vars(): Return character vector of all state variables.

  • mp_flow_vars(): Return the names of all variables that contain the absolute flow between compartments. The absolute flow is the magnitude of a flow per time step.

  • mp_state_flow_vars(): Union of mp_state_vars() and mp_flow_vars().

Examples

si = mp_tmb_library("starter_models", "si", package = "macpan2")
(si
  |> mp_simulator(time_steps = 5L, mp_state_vars(si))
  |> mp_trajectory()
)
#>    matrix time row col     value
#> 1       I    1   0   0  1.198000
#> 2       S    1   0   0 98.802000
#> 3       I    2   0   0  1.434730
#> 4       S    2   0   0 98.565270
#> 5       I    3   0   0  1.717559
#> 6       S    3   0   0 98.282441
#> 7       I    4   0   0  2.055170
#> 8       S    4   0   0 97.944830
#> 9       I    5   0   0  2.457757
#> 10      S    5   0   0 97.542243