Residual degrees of freedom for an Emax regression model

Returns the residual degrees of freedom, equal to the number of observations minus the number of estimated parameters.

Usage

# S3 method for class 'emaxlogistic'
df.residual(object, ...)

# S3 method for class 'emaxnls'
df.residual(object, ...)

Arguments

object

An emaxnls or emaxlogistic object

...

Ignored

Value

A numeric scalar

Details

For emaxnls objects, the value is obtained directly from the underlying nls fit. For emaxlogistic objects, it is computed as nobs(object) - length(coef(object)).

Examples

mod_c <- emax_nls(
  structural_model = rsp_1 ~ exp_1,
  covariate_model = list(E0 ~ cnt_a, Emax ~ 1, logEC50 ~ 1),
  data = emax_df,
  opts = emax_nls_options(max_time = 10)
)
df.residual(mod_c)
#> [1] 396

mod_b <- emax_logistic(
  structural_model = rsp_2 ~ exp_1,
  covariate_model = list(E0 ~ cnt_a, Emax ~ 1, logEC50 ~ 1),
  data = emax_df,
  opts = emax_logistic_options(max_time = 10)
)
df.residual(mod_b)
#> [1] 396