DNase {datasets} | R Documentation

## Elisa assay of DNase

### Description

The `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 `c("nfnGroupedData", "nfGroupedData", "groupedData", "data.frame")` containing the following columns:

Run

  an ordered factor with levels `10` < ... < `3` indicating the assay run.

conc

  a numeric vector giving the known concentration of the protein.

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 `nlme`, and that has methods (including for `[`, `as.data.frame`, `plot` and `print`) for its grouped-data classes.

### Source

Davidian, M. and Giltinan, D. M. (1995) Nonlinear Models for Repeated Measurement Data, Chapman & Hall (section 5.2.4, p. 134)

Pinheiro, J. C. and Bates, D. M. (2000) Mixed-effects Models in S and S-PLUS, Springer.

### Examples

    require(stats); require(graphics)

    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)

[Package datasets version 3.4.2 Index]