R: Glaucoma Database

GlaucomaM {TH.data} | R Documentation

## Glaucoma Database

### Description

The `GlaucomaM` data has 196 observations in two classes. 62 variables are derived from a confocal laser scanning image of the optic nerve head, describing its morphology. Observations are from normal and glaucomatous eyes, respectively.

### Usage

    data("GlaucomaM")

### Format

This data frame contains the following predictors describing the morphology of the optic nerve head and a membership variable:

ag

  area global.

at

  area temporal.

as

  area superior.

an

  area nasal.

ai

  area inferior.

eag

  effective area global.

eat

  effective area temporal.

eas

  effective area superior.

ean

  effective area nasal.

eai

  effective area inferior.

abrg

  area below reference global.

abrt

  area below reference temporal.

abrs

  area below reference superior.

abrn

  area below reference nasal.

abri

  area below reference inferior.

hic

  height in contour.

mhcg

  mean height contour global.

mhct

  mean height contour temporal.

mhcs

  mean height contour superior.

mhcn

  mean height contour nasal.

mhci

  mean height contour inferior.

phcg

  peak height contour.

phct

  peak height contour temporal.

phcs

  peak height contour superior.

phcn

  peak height contour nasal.

phci

  peak height contour inferior.

hvc

  height variation contour.

vbsg

  volume below surface global.

vbst

  volume below surface temporal.

vbss

  volume below surface superior.

vbsn

  volume below surface nasal.

vbsi

  volume below surface inferior.

vasg

  volume above surface global.

vast

  volume above surface temporal.

vass

  volume above surface superior.

vasn

  volume above surface nasal.

vasi

  volume above surface inferior.

vbrg

  volume below reference global.

vbrt

  volume below reference temporal.

vbrs

  volume below reference superior.

vbrn

  volume below reference nasal.

vbri

  volume below reference inferior.

varg

  volume above reference global.

vart

  volume above reference temporal.

vars

  volume above reference superior.

varn

  volume above reference nasal.

vari

  volume above reference inferior.

mdg

  mean depth global.

mdt

  mean depth temporal.

mds

  mean depth superior.

mdn

  mean depth nasal.

mdi

  mean depth inferior.

tmg

  third moment global.

tmt

  third moment temporal.

tms

  third moment superior.

tmn

  third moment nasal.

tmi

  third moment inferior.

mr

  mean radius.

rnf

  retinal nerve fiber thickness.

mdic

  mean depth in contour.

emd

  effective mean depth.

mv

  mean variability.

Class

  a factor with levels `glaucoma` and `normal`.

### Details

All variables are derived from a laser scanning image of the eye background taken by the Heidelberg Retina Tomograph. Most of the variables describe either the area or volume in certain parts of the papilla and are measured in four sectors (temporal, superior, nasal and inferior) as well as for the whole papilla (global). The global measurement is, roughly, the sum of the measurements taken in the four sector.

The observations in both groups are matched by age and sex to prevent any bias.

### Source

Torsten Hothorn and Berthold Lausen (2003), Double-Bagging: Combining classifiers by bootstrap aggregation. Pattern Recognition, 36(6), 1303–1309.

[Package TH.data version 1.0-9 Index]