drmOrdinal: Fitting ordinal dose-response models

In DoseResponse/bmd: Benchmark dose estimation for dose-response data

Fitting ordinal dose-response models

Description

A model fitting function for analysis of ordinal dose-response data.

Usage

drmOrdinal(levels, dose, weights, data, fct, p.epsilon = 10^(-16))

Arguments

levels	a character vector of the levels of the response variable in increasing order, as they appear in the supplied data set
dose	a character string specifying the column with the dose values in the supplied data set
weights	a character string specifying the column containing the number of observations pr. group
blocks	a character string specifying the column containing the blocks of the experiment, if available (optional)
data	a dataframe containing the observations
fct	a list with three or more elements specifying the non-linear function, the accompanying self starter function, the names of the parameter in the non-linear function and, optionally, the first and second derivatives as well, for the individual fitted curves. For more information see the help page for the "drm" function in the "drc" package. Currently available functions for ordinal dose-response models include, among others, the log-logistic models LL.4, the log-normal model LN.4 and the two Weibull models W1.4 and W2.4. Use getMeanFunctions for a full list.
p.epsilon	numeric value specifying the lower bound for the probabilites for each level returned by the function pFun created when fitting the model. Default value is 10^(-16)

Details

This functions fits a dose-response model for ordinal dose-response data by fitting a series of binomial dose-response models.

Value

An object of (S3) class 'drcOrdinal'.

Author(s)

Signe M. Jensen and Jens Riis Baalkilde

References

# ADD REFERENCES

Examples

library(drcData)
data(guthion)
guthionS <- subset(guthion, trt == "S")

guthionS.LL <- drmOrdinal(levels = c("alive", "moribund", "dead"), weights = "total", dose = "dose", data = guthionS, fct = LL.2())

plot(guthionS.LL, xlim = c(15,55)) # uses ggplot

DoseResponse/bmd documentation built on March 29, 2025, 4:36 p.m.