hormesis {drc} | R Documentation |
Results from an experiment with isobutylalcohol in nutrient solution.
data(hormesis)
A data frame with 21 observations on the following 2 variables.
The data set illustrates hormesis, presence of a subtoxic stimulus.
van Ewijk, P. H. and Hoekstra, J. A. (1993) Calculation of the EC50 and its Confidence Interval When Subtoxic Stimulus Is Present, ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 25, 25–32.
van Ewijk, P. H. and Hoekstra, J. A. (1994) Curvature Measures and Confidence Intervals for the Linear Logistic Model, Appl. Statist., 43, 477–487.
## Look at data head(hormesis) ## Monotonous dose-response model hm.m1 <- drm(weight~conc, data=hormesis, fct=LL.3()) plot(hm.m1) ## Model fit in van Ewijk and Hoekstra (1994) hm.m2 <- drm(weight~conc, data=hormesis, fct=BC.4()) plot(hm.m2, type = "fit", add = TRUE, lty = 2) ## Hormesis effect only slightly significant summary(hm.m2) ## Hormesis effect highly significant anova(hm.m1,hm.m2)