This function peforms the four-parameter dose response curve fit. It is the helper function for the fit in the fit_drc_4p function.

drc_4p(data, response, dose, log_logarithmic = TRUE, pb = NULL)

## Arguments

data a data frame that contains at least the dose and response column the model should be fitted to. a numeric column that contains the response values. a numeric column that contains the dose values. a logical value indicating if a logarithmic or log-logarithmic model is fitted. If response values form a symmetric curve for non-log transformed dose values, a logarithmic model instead of a log-logarithmic model should be used. Usually biological dose response data has a log-logarithmic distribution, which is the reason this is the default. Log-logarithmic models are symmetric if dose values are log transformed. progress bar object. This is only necessary if the function is used in an iteration.

## Value

An object of class drc. If no fit was performed a character vector with content "no_fit".