| % File src/library/datasets/man/DNase.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2011 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{DNase} |
| \docType{data} |
| \alias{DNase} |
| \title{Elisa assay of DNase} |
| \description{ |
| The \code{DNase} data frame has 176 rows and 3 columns of data |
| obtained during development of an ELISA assay for the recombinant |
| protein DNase in rat serum. |
| } |
| \usage{DNase} |
| \format{ |
| An object of class |
| \code{c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame")} |
| containing the following columns: |
| \describe{ |
| \item{Run}{ |
| an ordered factor with levels \code{10} < \dots < \code{3} |
| indicating the assay run. |
| } |
| \item{conc}{ |
| a numeric vector giving the known concentration of the |
| protein. |
| } |
| \item{density}{ |
| a numeric vector giving the measured optical density |
| (dimensionless) in the assay. Duplicate optical density |
| measurements were obtained. |
| } |
| } |
| } |
| \details{ |
| This dataset was originally part of package \code{nlme}, and that has |
| methods (including for \code{[}, \code{as.data.frame}, \code{plot} and |
| \code{print}) for its grouped-data classes. |
| } |
| \source{ |
| Davidian, M. and Giltinan, D. M. (1995) |
| \emph{Nonlinear Models for Repeated Measurement Data}, |
| Chapman & Hall |
| (section 5.2.4, p.\sspace{}134) |
| |
| Pinheiro, J. C. and Bates, D. M. (2000) \emph{Mixed-effects Models in |
| S and S-PLUS}, Springer. |
| } |
| \examples{ |
| require(stats); require(graphics) |
| \dontshow{options(show.nls.convergence=FALSE)} |
| coplot(density ~ conc | Run, data = DNase, |
| show.given = FALSE, type = "b") |
| coplot(density ~ log(conc) | Run, data = DNase, |
| show.given = FALSE, type = "b") |
| ## fit a representative run |
| fm1 <- nls(density ~ SSlogis( log(conc), Asym, xmid, scal ), |
| data = DNase, subset = Run == 1) |
| ## compare with a four-parameter logistic |
| fm2 <- nls(density ~ SSfpl( log(conc), A, B, xmid, scal ), |
| data = DNase, subset = Run == 1) |
| summary(fm2) |
| anova(fm1, fm2) |
| } |
| \keyword{datasets} |