Acute inhalation — acute.inh • drc

Data from an acute inhalation toxicity test. For each of several dose levels, the total number of subjects and the number of dead subjects were recorded.

Usage

data(acute.inh)

Format

A data frame with 6 observations on the following 3 variables.

dose: a numeric vector
total: a numeric vector
num.dead: a numeric vector

Examples

library(drc)

## Displaying the data
head(acute.inh)
#>   dose total num.dead
#> 1  422     5        0
#> 2  744     5        1
#> 3  948     5        3
#> 4 2069     5        5

## Fitting a two-parameter log-logistic model for binomial response
acute.inh.m1 <- drm(num.dead/total ~ dose, weights = total,
data = acute.inh, fct = LL.2(), type = "binomial")
summary(acute.inh.m1)
#> 
#> Model fitted: Log-logistic (ED50 as parameter) with lower limit at 0 and upper limit at 1 (2 parms)
#> 
#> Parameter estimates:
#> 
#>               Estimate Std. Error t-value p-value    
#> b:(Intercept)  -7.9301     5.0812 -1.5607  0.1186    
#> e:(Intercept) 895.2982    83.5547 10.7151  <2e-16 ***
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

## Plotting the fitted curve
plot(acute.inh.m1, xlab = "Dose", ylab = "Proportion dead")