R: Dose-response profile of degradation of agrochemical using...

nasturtium {drc} | R Documentation

## Dose-response profile of degradation of agrochemical using nasturtium

### Description

Estimation of the degradation profile of an agrochemical based on soil samples at depth 0-10cm from a calibration experiment.

### Usage

    data(nasturtium)

### Format

A data frame with 42 observations on the following 2 variables.

`conc`

  a numeric vector of concentrations (g/ha)

`weight`

  a numeric vector of plant weight (mg) after 3 weeks' growth

### Details

It is an experiment with seven concentrations and six replicates per concentration. Nasturtium is sensitive and its weight reduces noticeable at low concentrations.

Racine-Poon (1988) suggests using a three-parameter log-logistic model.

### Source

Racine-Poon, A. (1988) A Bayesian Approach to Nonlinear Calibration Problems, J. Am. Statist. Ass., 83, 650–656.

### Examples

    nasturtium.m1 <- drm(weight~conc, data=nasturtium, fct = LL.3())

    modelFit(nasturtium.m1)

    plot(nasturtium.m1, type = "all", log = "", xlab = "Concentration (g/ha)", ylab = "Weight (mg)")

[Package drc version 3.0-1 Index]