Model deviance for an Emax regression model — deviance.emaxlogistic • emaxnls

Returns a scalar measure of the overall lack of fit. The two model classes use different definitions of deviance that reflect their different likelihoods. Both measures decrease as the fit improves and are used internally by anova() for model comparison.

Usage

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

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

Arguments

object: An emaxnls or emaxlogistic object
...: Ignored

Value

A numeric scalar. For emaxnls objects, returns the residual sum of squares. For emaxlogistic objects, returns the binomial deviance (-2 * logLik).

Examples

# emaxnls deviance (residual sum of squares)
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)
)
deviance(mod_c)
#> [1] 103.306

# emaxlogistic deviance (binomial deviance)
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)
)
deviance(mod_b)
#> [1] 331.4698