invivoPKfit (version 2.0.2)

get_starts_httk_gas_pbtk: Get starting values for httk `gas_pbtk` model with specific clearance

Description

Derive starting values for PBTK model parameters from available data

Usage

get_starts_httk_gas_pbtk(
  data,
  par_DF,
  this_chemical,
  this_species,
  restrictive,
  ...
)

Value

The same `data.frame` as `par_DF`, with an additional variable `starts` containing the derived starting value for each parameter. If a parameter cannot be estimated from the available data, then its starting value will be `NA_real_`

Arguments

data

The data set to be fitted (e.g. the result of [preprocess_data()])

par_DF

A `data.frame` with the following variables

• `param_name`: Character: Names of the model parameters

• `param_units`: Character: Units of the model parameters

• `optimize_param`: TRUE if each parameter is to be estimated from the data; FALSE otherwise

• `use_param`: TRUE if each parameter is to be used in evaluating the model; FALSE otherwise

• `lower_bounds`: Numeric: The lower bounds for each parameter

• `upper_bounds`: Numeric: The upper bounds for each parameter

this_chemical

A character vector naming the chemical for calculations in `httk`.

this_species

A character vector naming the species for calculations in `httk`.

restrictive

A boolean value determinining whether to assume restrictive or non-restrictive clearance when getting starting values.

...

Additional parameters, currently only list of character vectors describing parameters to optimize or parameter start values.

Additional parameters

There are also additional parameters calculated to allow recalculation of parameters during fitting. These include `fabs.oral`, `Fprotein.plasma`, and `Qintestinetrasport`.

Author

Gilberto Padilla Mercado

Details

This function is called internally by [get_params_httk_gas_pbtk()] and should generally not be called directly by the user.

The full set of model parameters is given by the parameterize_3comp2 function in `httk`.

Not all of the parameters are intended to be optimized. Currently, only `Clint`, `Funbound.plasma`, or any of the model's partitioning coefficients can be optimized.

See Also

Other httk model functions: auc_httk_gas_pbtk(), cp_httk_gas_pbtk(), get_params_httk_gas_pbtk()

Other get_starts functions: get_starts_1comp(), get_starts_2comp(), get_starts_flat()

Other built-in model functions: auc_1comp(), auc_2comp(), auc_flat(), auc_httk_gas_pbtk(), cp_1comp(), cp_2comp(), cp_2comp_dt(), cp_flat(), cp_httk_gas_pbtk(), get_params_1comp(), get_params_2comp(), get_params_flat(), get_params_httk_gas_pbtk(), get_starts_1comp(), get_starts_2comp(), get_starts_flat(), tkstats_2comp(), transformed_params_2comp()