# Parameters for transition model

Source: `R/transmod.R`
`create_transmod_params.Rd`

Extract parameters from a multi-state NMA for use with the data table returned by `create_transmod_data`, which are used to simulate health state transitions with a continuous time state transition model (CTSTM).

    create_transmod_params(n = 100, data,
      params_mstate_nma = iviNSCLC::params_mstate_nma, check_covs = FALSE,
      covs = NULL)

## Arguments

n | The number of random observations of the parameters to draw.
data | A data table of class "expanded_hesim_data" returned from `create_transmod_data`.
params_mstate_nma | A list of `params_surv` objects, where each element in the list denotes a survival distribution. Should have the same variable names as `params_mstate_nma`.
check_covs | Logical indicating whether to check that all covariates in `data` are contained in `params`.
covs | If `check_covs` is `TRUE`, then `data_covs` cannot be `NULL` and must specify all of the covariates in `data` that should be contained in `params`.

## Value

A `params_surv` objects from the hesim package.

## Details

The "dist" attribute from `data` is used to select a survival distribution from the `mstate_nma` element contained in `params`. The covariates for the selected survival distribution in `mstate_nma` that are also contained in `data` are extracted.

## See also

`create_transmod`, `create_transmod_data`