R: Testing if there is a dose effect at all

noEffect {drc} | R Documentation

## Testing if there is a dose effect at all

### Description

A significance test is provided for the comparison of the dose-response model considered and the simple linear regression model with slope 0 (a horizontal regression line corresponding to no dose effect)

### Usage

    noEffect(object)

### Arguments

`object` | an object of class 'drc'.

### Details

Perhaps useful for screening purposes.

### Value

The likelihood ratio test statistic and the corresponding degrees of freedom and p-value are reported.

### Author(s)

Christian Ritz

### Examples

    ryegrass.LL.4 <- drm(rootl ~ conc, data = ryegrass, fct = LL.4())

    noEffect(ryegrass.LL.4)
    # p-value < 0.0001: there is a highly significant dose effect!

[Package drc version 3.0-1 Index]