lizards: Habitat Preferences of Lizards

In brglm: Bias Reduction in Binomial-Response Generalized Linear Models

Description

The lizards data frame has 23 rows and 6 columns. Variables grahami and opalinus are counts of two lizard species at two different perch heights, two different perch diameters, in sun and in shade, at three times of day.

Usage

data(lizards)

Format

This data frame contains the following columns:

grahami

count of grahami lizards

opalinus

count of opalinus lizards

height

a factor with levels "<5ft", ">=5ft"

diameter

a factor with levels "<=2in", ">2in"

light

a factor with levels "sunny", "shady"

time

a factor with levels "early", "midday", "late"

Source

McCullagh, P. and Nelder, J. A. (1989) Generalized Linear Models (2nd Edition). London: Chapman and Hall.

Originally from

Schoener, T. W. (1970) Nonsynchronous spatial overlap of lizards in patchy habitats. Ecology 51, 408–418.

Examples

data(lizards)
glm(cbind(grahami, opalinus) ~ height + diameter + light + time,
    family = binomial, data=lizards)
brglm(cbind(grahami, opalinus) ~ height + diameter + light + time,
    family = binomial, data=lizards)

Example output

Loading required package: profileModel
'brglm' will gradually be superseded by 'brglm2' (https://cran.r-project.org/package=brglm2), which provides utilities for mean and median bias reduction for all GLMs and methods for the detection of infinite estimates in binomial-response models.

Call:  glm(formula = cbind(grahami, opalinus) ~ height + diameter + 
    light + time, family = binomial, data = lizards)

Coefficients:
 (Intercept)   height>=5ft  diameter>2in    lightshady    timemidday  
      1.9447        1.1300       -0.7626       -0.8473        0.2271  
    timelate  
     -0.7368  

Degrees of Freedom: 22 Total (i.e. Null);  17 Residual
Null Deviance:	    70.1 
Residual Deviance: 14.2 	AIC: 83.03

Call:  brglm(formula = cbind(grahami, opalinus) ~ height + diameter +      light + time, family = binomial, data = lizards) 

Coefficients:
 (Intercept)   height>=5ft  diameter>2in    lightshady    timemidday  
      1.9018        1.1064       -0.7536       -0.8177        0.2280  
    timelate  
     -0.7273  

Degrees of Freedom: 22 Total (i.e. Null);  17 Residual
Deviance:	    14.2462 
Penalized Deviance: -4.0065 	AIC: 83.0704 

brglm documentation built on April 22, 2021, 5:07 p.m.