secalonic {drc} | R Documentation |
Data are from an experiment assessing the inhibitory effect of secalonic acids on plant growth.
data(secalonic)
A data frame with 7 observations on the following 2 variables:
dose
rootl
Data are averages of three root length measurements.
Gong, X. and Zeng, R. and Luo, S. and Yong, C. and Zheng, Q. (2004) Two new secalonic acids from Aspergillus Japonicus and their allelopathic effects on higher plants, Proceedings of International Symposium on Allelopathy Research and Application, 27-29 April, Shanshui, Guangdong, China (Editors: R. Zeng and S. Luo), 209–217.
## Fitting a four-parameter log-logistic model secalonic.m1 <- drm(rootl ~ dose, data = secalonic, fct = LL.4()) summary(secalonic.m1) ## Fitting a three-parameter log-logistic model ## lower limit fixed at 0 secalonic.m2 <- drm(rootl ~ dose, data = secalonic, fct = LL.3()) summary(secalonic.m1) ## Fitting logistic and log-logistic models secalonic.m1 <- drm(rootl ~ dose, data = secalonic, fct = LL.4()) secalonic.m2 <- drm(rootl ~ dose, data = secalonic, fct = L.4()) plot(secalonic.m1, conLevel=0.001, broken=TRUE, ylim=c(0,7), xlab="Dose", ylab="Root length", cex=1.2, lwd=2) plot(secalonic.m2, conLevel=0.001, broken=TRUE, ylim=c(0,7), add=TRUE, lty=2, lwd=2) abline(h=coef(secalonic.m2)[3], lty=3, lwd=2)