statforbiology (version 0.9.9)

compCurves: Compare regression curves in a pairwise fashion

Description

For regression models containing grouping factors and fitted with the 'drm' function in the 'drc' package, this function compares the different curves for each factor level in a pairwise fashion, according to a series of F tests for the extra-sum-of-squares. Works only with 'drc' objects

Usage

compCurves(
  obj,
  adjusted = c("none", "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr")
)

Value

returns a list with two slots: (i) Pairs: the list of peirwise comparisons, with F values and P-values; (ii) Letters: letter display for the different curves

Arguments

obj

a drc object

adjusted

a character string, for selecting the method of multiplicity correction. Must be one of: c("none", "holm", "hochberg", "hommel", "bonferroni", "BH", "BY", "fdr")

Author

Andrea Onofri

Examples

metamitron <- getAgroData("metamitron")
head(metamitron)
tail(metamitron)

mod1 <- drm(Conc ~ Time, fct = DRC.expoDecay(),
               curveid = Herbicide,
               data = metamitron)
summary(mod1)
compCurves(mod1, adjusted = "bonferroni")