# Analytically determine the operating characteristics of a multi-stage group-sequential multi-arm clinical trial for a Poisson distributed primary outcome

Source: `R/opchar_gs_pois.R`
`opchar_gs_pois.Rd`

`opchar_gs_pois()` determines the operating characteristics of a specified multi-stage group-sequential multi-arm clinical trial design assuming the primary outcome variable is Poisson distributed, for given values of the true treatment effects, using multivariate normal integration.

    opchar_gs_pois(des = des_gs_pois(), lambda, summary = FALSE)

## Arguments

des | A `list` of class `"multiarm_des_gs_pois"`, as returned by `build_gs_pois` or `des_gs_pois` (i.e., a multi-stage group-sequential multi-arm clinical trial design for a Poisson distributed outcome). Defaults to `des_gs_pois()`.
lambda | A `matrix` whose rows indicate values of λ at which to evaluate the operating characteristics. Defaults internally to the global null, global alternative, and each of the least favourable configurations, for the specified design `des`.
summary | A `logical` variable indicating whether a summary of the function's progress should be printed to the console. Defaults to `FALSE`.

## Value

A `list` containing the following elements

- A `tibble` in the slot `$opchar` giving the determined operating characteristics.

- A `tibble` in the slot `$pmf_N` giving the determined probability mass functions of the random required sample size.

- Each of the input variables.

## See also

`build_gs_pois`, `des_gs_pois`, `plot.multiarm_des_gs_pois`, `sim_gs_pois`.

## Examples

    # The operating characteristics for the default parameters
    opchar        <- opchar_gs_pois()