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drc (version 4.0-0)

Dose-Response Analysis Using R

Description

Analysis of various types of dose-response data is enabled through a suite of flexible and versatile model fitting and after-fitting functions. A wide range of dose-response models is available.

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Install

install.packages('drc')

Monthly Downloads

163,071

Version

4.0-0

License

GPL-2

Issues

30

Pull Requests

4

Stars

29

Forks

19

Maintainer

Christian Ritz

Last Published

September 29th, 2026

Functions in drc (4.0-0)

NEC

Dose-response model for estimation of no effect concentration (NEC).
PR

Expected or predicted response
RScompetition

Competition between two biotypes
acidiq

Acifluorfen and diquat tested on Lemna minor.
W1.4

The four-parameter Weibull functions
S.alba

Potency of two herbicides
S.capricornutum

Effect of cadmium on growth of green alga
auxins

Effect of technical grade and commercially formulated auxin herbicides
coef.drc

Extract Model Coefficients
algae

Volume of algae as function of increasing concentrations of a herbicide
compParm

Comparison of parameters
anova.drc

ANOVA for dose-response model fits
cedergreen

The Cedergreen-Ritz-Streibig model
chickweed

Germination of common chickweed (Stellaria media)
W1.3

The three-parameter Weibull functions
bread.drc

Bread and meat for the sandwich
backfit

Calculation of backfit values from a fitted dose-response model
W1.2

The two-parameter Weibull functions
braincousens

The Brain-Cousens hormesis models
daphnids

Daphnia test
boxcox.drc

Transform-both-sides Box-Cox transformation
baro5

The modified baro5 function
earthworms

Earthworm toxicity test
deguelin

Deguelin applied to chrysanthemum aphis
etmotc

Effect of erythromycin on mixed sewage microorganisms
confint.drc

Confidence Intervals for model parameters
drmc

Sets control arguments
comped

Comparison of effective dose values
lepidium

Dose-response profile of degradation of agrochemical using lepidium
drm

Fitting dose-response models
lettuce

Hormesis in lettuce plants
finney71

Example from Finney (1971)
decontaminants

Performance of decontaminants used in the culturing of a micro-organism
germination

Germination of three crops
gompertz

Mean function for the Gompertz dose-response or growth curve
getInitial

Showing starting values used
hatvalues.drc

Model diagnostics for nonlinear dose-response models
isobole

Creating isobolograms
gompertzd

The derivative of the Gompertz function
gammadr

Gamma dose-response model
gaussian

Normal and log-normal biphasic dose-response models
leaflength

Leaf length of barley
glymet

Glyphosate and metsulfuron-methyl tested on algae.
heartrate

Heart rate baroreflexes for rabbits
methionine

Weight gain for different methionine sources
modelFit

Assessing the model fit
getMeanFunctions

Display available dose-response models
nasturtium

Dose-response profile of degradation of agrochemical using nasturtium
metals

Data from heavy metal mixture experiments
mecter

Mechlorprop and terbythylazine tested on Lemna minor
mselect

Dose-response model selection
logLik.drc

Extracting the log likelihood
multi2

Multistage dose-response model with quadratic terms
fitted.drc

Extract fitted values from model
lnormal

Log-normal dose-response model
fplogistic

Fractional polynomial-logistic dose-response models
plot.drc

Plotting fitted dose-response curves
terbuthylazin

The effect of terbuthylazin on growth rate
print.summary.drc

Printing summary of non-linear model fits
update.drc

Updating and re-fitting a model
rdrm

Simulating a dose-response curve
noEffect

Testing if there is a dose effect at all
mixture

Fitting binary mixture models
spinach

Inhibition of photosynthesis
mr.test

Mizon-Richard test for dose-response models
summary.drc

Summarising non-linear model fits
print.drc

Printing key features
neill.test

Neill's lack-of-fit test for dose-response models
predict.drc

Prediction
secalonic

Root length measurements
vcov.drc

Calculating variance-covariance matrix for objects of class 'drc'
twophase

Two-phase dose-response model
searchdrc

Searching through a range of initial parameter values to obtain convergence
ursa

Model function for the universal response surface approach (URSA) for the quantitative assessment of drug interaction
vinclozolin

Vinclozolin from AR in vitro assay
lin.test

Lack-of-fit test for the mean structure based on cumulated residuals
simDR

Simulating ED values under various scenarios
selenium

Data from toxicology experiments with selenium
llogistic

The log-logistic function
maED

Estimation of ED values using model-averaging
logistic

The logistic model
ryegrass

Effect of ferulic acid on growth of ryegrass
residuals.drc

Extracting residuals from the fitted dose-response model
weibull1

Weibull model functions
yieldLoss

Calculating yield loss parameters
CRS.5a

Cedergreen-Ritz-Streibig dose-reponse model for describing hormesis
CIcompX

Calculation of combination index for binary mixtures
G.aparine

Herbicide applied to Galium aparine
H.virescens

Mortality of tobacco budworms
EXD

Exponential decay model
BC.5

The Brain-Cousens hormesis models
CRS.4a

The Cedergreen-Ritz-Streibig model
ED.drc

Estimating effective doses
EDcomp

Comparison of relative potencies between dose-response curves
AR

Asymptotic regression model
O.mykiss

Test data from a 21 day fish test
LL.4

The four-parameter log-logistic function
LL.5

The five-parameter log-logistic function
LL.3

The three-parameter log-logistic function
M.bahia

Effect of an effluent on the growth of mysid shrimp
P.promelas

Effect of sodium pentachlorophenate on growth of fathead minnow
MAX

Maximum mean response
MM

Michaelis-Menten model
LL.2

The two-parameter log-logistic function