# Dividing age by 100 (age covariate)

**URL:** https://isgw-forum.colorado.edu/t/dividing-age-by-100-age-covariate/652
**Category:** Twin & family modeling
**Created:** [October 31, 2024, 11:11pm UTC](https://isgw-forum.colorado.edu/t/dividing-age-by-100-age-covariate/652 "2024-10-31T23:11:23Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![jamal.giri](https://isgw-forum.colorado.edu/letter_avatar_proxy/v4/letter/j/b5ac83/32.png) [@jamal.giri](https://isgw-forum.colorado.edu/u/jamal.giri)
#### Post date: [October 31, 2024, 11:11pm UTC](https://isgw-forum.colorado.edu/t/dividing-age-by-100-age-covariate/652/1 "2024-10-31T23:11:23Z")

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Hi,

I’m trying to run a one-phenotype (continuous) ACE model with age as a covariate (oneACEvca.R) for my twin data. I noticed that in the script from Hermine Maes’s website, the age variable is divided by 100. is it mandatory to divide age with 100?  
Here’s the relevant part of the script:

# Select Covariates for Analysis

twinData[,‘age’] ← twinData[,‘age’]/100  
twinData ← twinData[-which(is.na(twinData$age)),]  
covVars ← ‘age’

Thanks.