drc (version 1.2-0)

isobole: Creating isobolograms

Description

'isobole' displays isobole based on EC/ED50 estimates from a log-logistic model. Additionally isoboles determined by the concentration addition model or Hewlett's model can be added to the plot.

Usage

isobole(object1, object2, ename = "e", xaxis = "0", exchange, xlab = "A", ylab = "B", xlim, ylim, ...)

Arguments

object1

object of class 'drc' where EC/ED50 parameters vary freely.

object2

object of class 'drc' where EC/ED50 parameters vary according to Hewlett's model.

ename

character string. The name of the EC/ED50 variable.

xaxis

character string. Is the mixture "0:100" or "100:0" on the x axis?

exchange

numeric. The exchange rate between the two substances.

xlab

an optional label for the x axis.

ylab

an optional label for the y axis.

xlim

a numeric vector of length two, containing the lower and upper limit for the x axis.

ylim

a numeric vector of length two, containing the lower and upper limit for the y axis.

...

Additional graphical parameters.

Details

Only to be used with the function mixture.

Examples

## Fitting the model with freely varying ED50 values
model1 <- multdrc(rgr1~dose1, pct1, data=acidiq, 
collapse = list(~factor(pct1),~1,~1,~factor(pct1) - 1), 
boxcox = TRUE)

## Fitting the concentration addition model
model1ca <- mixture(rgr1~dose1, pct1, data=acidiq, 
collapse = ~factor(pct1), 
model = "CA", boxcox = TRUE)

## Fitting the Hewlett model
model1h <- mixture(rgr1~dose1, pct1, data=acidiq, 
collapse = ~factor(pct1), 
model = "Hewlett", boxcox = TRUE)

## Isobologram with freely varying EC/ED50 values
isobole(model1, exchange=0.1, xlim=c(0,450), ylim=c(0,45))

## Isobologram based on concentration addition
isobole(model1, model1ca, exchange=0.1, xlim=c(0,450), ylim=c(0,45), 
main="Concentration Addition")

## Isobologram based on Hewlett's model
isobole(model1, model1h, exchange=0.1, xlim=c(0,450), ylim=c(0,45), 
main="Hewlett")

rm(model1, model1ca, model1h)