A call to rw() can be used in the 'formula' argument of model
construction functions in the epinowcast package such as enw_formula().
Does not evaluate arguments but instead simply passes information for use in
model construction.
Usage
rw(time, by, type = c("independent", "dependent"))Arguments
- time
Defines the random walk time period.
- by
Defines the grouping parameter used for the random walk. If not specified no grouping is used. Currently this is limited to a single variable.
- type
Character string, how standard deviation of grouped random walks is estimated: "independent", or "dependent" across groups; enforced by
base::match.arg().
Value
A list defining the time frame, group, and type with class
"enw_rw_term" that can be interpreted by construct_rw().
See also
Functions used to help convert formulas into model designs
as_string_formula(),
construct_re(),
construct_rw(),
enw_formula(),
enw_manual_formula(),
parse_formula(),
remove_rw_terms(),
re(),
rw_terms(),
split_formula_to_terms()
Examples
rw(time)
#> $time
#> [1] "time"
#>
#> $by
#> NULL
#>
#> $type
#> [1] "independent"
#>
#> attr(,"class")
#> [1] "enw_rw_term"
rw(time, location)
#> $time
#> [1] "time"
#>
#> $by
#> [1] "location"
#>
#> $type
#> [1] "independent"
#>
#> attr(,"class")
#> [1] "enw_rw_term"
rw(time, location, type = "dependent")
#> $time
#> [1] "time"
#>
#> $by
#> [1] "location"
#>
#> $type
#> [1] "dependent"
#>
#> attr(,"class")
#> [1] "enw_rw_term"