R: Maximum mean response

MAX {drc} | R Documentation

## Maximum mean response

### Description

`MAX` estimates the maximum mean response and the dose at which it occurs.

### Usage

    MAX(object, lower = 1e-3, upper = 1000, pool = TRUE)

### Arguments

`object` | an object of class 'drc'.
`lower` | numeric. Lower limit for bisection method. Need to be smaller than EDx level to be calculated.
`upper` | numeric. Upper limit for bisection method. Need to be larger than EDx level to be calculated.
`pool` | logical. If TRUE curves are pooled. Otherwise they are not. This argument only works for models with independently fitted curves as specified in `drm`.

### Details

This function is only implemented for the built-in functions of class `braincousens` and `cedergreen`.

This function was used for obtaining the results on hormesis effect size reported in Cedergreen et al. (2005).

### Value

A matrix with one row per curve in the data set and two columns: one containing the dose at which the maximum occurs and one containing the corresponding maximum response.

### Author(s)

Christian Ritz

### References

Cedergreen, N. and Ritz, C. and Streibig, J. C. (2005) Improved empirical models describing hormesis, Environmental Toxicology and Chemistry 24, 3166–3172.

### Examples

    ## Fitting a Cedergreen-Ritz-Streibig model
    lettuce.m1 <- drm(weight~conc, data = lettuce, fct = CRS.4c())

    ## Finding maximum average response and the corrresponding dose
    MAX(lettuce.m1)

[Package drc version 3.0-1 Index]