This function applies probit transformation to the data, after applying Abbott's correction (see reference) when control groups (e.g. unexposed susceptible strain) show non-negligible mortality.
Arguments
- dataf
a data frame of mortality data containing four mandatory columns "strain", "dose", "total", "dead" (not necessarily in that order).
- conf
numerical. Threshold for the mortality in the controls above which the correction should be applied (default=0.05)
Value
Returns a list. convrg: with correction values and convergence (NULL if mortality in the controls is below conf.), tr.data: transformed data
References
Abbott, WS (1925). A method of computing the effectiveness of an insecticide. J. Econ. Entomol.;18:265‐267.
Examples
data(bioassay)
transd<-probit.trans(bioassay)