babies: Crying Babies Data

In cond: Approximate Conditional Inference for Logistic and Loglinear Models

Description

The babies data frame has 36 rows and 4 columns.

Matched pairs of binary observations concerning the crying of babies. The babies were observed on 18 days and on each day one child was lulled. Interest focuses on the treatment effect “lulling”.

Usage

data(babies)

Format

This data frame contains the following columns:

r1

number of children not crying on one day;

r2

number of children crying on one day;

lull

indicator variable for the treatment;

day

factor variable for the days.

Source

The data were obtained from

Cox, D. R. (1970) Analysis of Binary Data (page 61). London: Chapman \& Hall.

References

Davison, A. C. (1988) Approximate conditional inference in generalized linear models. J. R. Statist. Soc. B, 50, 445–461.

Examples

data(babies)
coplot(r2/(r1+r2) ~ day | lull, data = babies)
##
babies.glm <- glm(formula = cbind(r1, r2) ~ day + lull - 1, 
                  family = binomial, data = babies)
babies.cond <- cond(object = babies.glm, offset = lullyes)
babies.cond
##
## If one wishes to avoid the generalized linear model fit:
babies.cond <- cond.glm(formula = cbind(r1, r2) ~ day + lull - 1, 
                        family = binomial, data = babies, offset = lullyes)
babies.cond

Example output

Loading required package: statmod
Loading required package: survival

   Package "cond" 1.2-3 (2014-06-27) 
    Copyright (C) 2000-2014 A. R. Brazzale

 This is free software, and you are welcome to redistribute
 it and/or modify it under the terms of the GNU General
 Public License published by the Free Software Foundation.
 Package "cond" comes with ABSOLUTELY NO WARRANTY.

 type `help(package="cond")' for summary information

Call:
cond.glm(object = babies.glm, offset = lullyes)

Formula:  cbind(r1, r2) ~ day + lull - 1
Family:  binomial
Offset:  lullyes

          Estimate   Std. Error 
uncond.       1.432       0.7341
cond.         1.270       0.6888

Diagnostics: 
    INF      NP 
0.07596 0.28882 

 Approximation based on 20 points
Call:
cond.glm(offset = lullyes, formula = cbind(r1, r2) ~ day + lull - 
    1, family = binomial, data = babies)

Formula:  cbind(r1, r2) ~ day + lull - 1
Family:  binomial
Offset:  lullyes

          Estimate   Std. Error 
uncond.       1.432       0.7341
cond.         1.270       0.6888

Diagnostics: 
    INF      NP 
0.07596 0.28882 

 Approximation based on 20 points

cond documentation built on May 2, 2019, 6:45 a.m.