# Medfly Data

### Description

Medfly data from the Carey et al (1992) experiment. There are 1,203,646 uncensored survival times!

### Usage

1 | ```
flies
``` |

### Format

A data frame with 19072 observations on the following 17 variables.

`age`

age at death in days`num`

frequency count of age at death`prcurr`

current proportion male`current`

current density`cohort`

cohort/pupal batch`size`

pupal size`cage`

cage number`female`

female = 1`cumul`

cumulative density`prcumu`

cumulative proportion male`begin`

initial cage density`prbegin`

initial proportion mail`size4`

size group 4`size5`

size group 5`size6`

size group 6`size7`

size group 7`size8`

size group 8

### Details

Quoting from Carey et al (1992) “...Pupae were sorted into one of five size classes using a pupal sorter. This enabled size dimorphism to be eliminated as a potential source of sex-specific mortality differences. Approximately, 7,200 medflies (both sexes) of a given size class were maintained in each of 167 mesh covered, 15 cm by 60 cm by 90 cm aluminum cages. Adults were given a diet of sugar and water, ad libitum, and each day dead flies were removed, counted and their sex determined ...”

### References

Carey, J.R., Liedo, P., Orozco, D. and Vaupel, J.W. (1992)
Slowing of mortality rates at older ages in large Medfly cohorts,
*Science,* 258, 457-61.

Koenker, R. and O. Geling (2001) Reappraising Medfly Longevity:
A Quantile Regression Survival Analysis, *J. Am. Stat. Assoc*,
96, 458-468.

Koenker, R. and Jiaying Gu, (2013) “Frailty, Profile Likelihood and Medfly
Mortality,” * Contemporary Developments in Statistical Theory:
A Festschrift for Hira Lal Koul*, S.N. Lahiri, A. Schick, Ashis Sengupta,
and T.N. Sriram, (eds.), Springer.