R: ANOVA for dose-response model fits

anova.drc {drc} | R Documentation

## ANOVA for dose-response model fits

### Description

'anova' produces an analysis of variance table for one or two non-linear model fits.

### Usage

      ## S3 method for class 'drc'
    anova(object, ..., details = TRUE, test = NULL)

### Arguments

`object` | an object of class 'drc'.
`...` | additional arguments.
`details` | logical indicating whether or not details on the models compared should be displayed. Default is TRUE (details are displayed).
`test` | a character string specifying the test statistic to be applied. Use "od" to assess overdispersion for binomial data.

### Details

Specifying only a single object gives a test for lack-of-fit, comparing the non-linear regression model to a more general one-way or two-way ANOVA model.

If two objects are specified a test for reduction from the larger to the smaller model is given. (This only makes statistical sense if the models are nested, that is: one model is a submodel of the other model.)

### Value

An object of class 'anova'.

### Author(s)

Christian Ritz

### References

Bates, D. M. and Watts, D. G. (1988) Nonlinear Regression Analysis and Its Applications, New York: Wiley \& Sons (pp. 103–104)

### See Also

For comparison of nested or non-nested model the function `mselect`can also be used.

The function `anova.lm` for linear models.

### Examples

    ## Comparing a Gompertz three- and four-parameter models using an F test
    ryegrass.m1 <- drm(rootl ~ conc, data = ryegrass, fct = W1.4())
    ryegrass.m2 <- drm(rootl ~ conc, data = ryegrass, fct = W1.3())
    anova(ryegrass.m2, ryegrass.m1)  # reduction to 'W1.3' not possible (highly significant)

    anova(ryegrass.m2, ryegrass.m1, details = FALSE)  # without details

[Package drc version 3.0-1 Index]