twin_NA_dot_data: Twin biometric data (Practice cleaning: "." for missing data,...

In OpenMx: Extended Structural Equation Modelling

Twin biometric data (Practice cleaning: "." for missing data, wrong data types etc.)

Description

Data set used in some of OpenMx's examples.

Usage

data("twin_NA_dot")

Format

A data frame with 3808 observations on the following variables.

fam

Family ID variable

age

Age of the twin pair. Range: 17 to 88, coded as factor

zyg

Integer codes for zygosity and gender combinations

part

Cohort

wt1

Weight in kilograms for twin 1 (this and following have "." embedded as NA...)

wt2

Weight in kilograms for twin 2

ht1

Height in meters for twin 1

ht2

Height in meters for twin 2

htwt1

Product of ht and wt for twin 1

htwt2

Product of ht and wt for twin 2

bmi1

Body Mass Index for twin 1

bmi2

Body Mass Index for twin 2

Details

Same as myTwinData but has . as the missing data value instead of NA.

Source

Timothy Bates

References

The OpenMx User's guide can be found at https://openmx.ssri.psu.edu/documentation/.

Examples

data(twin_NA_dot)
summary(twin_NA_dot)
# Note that all variables are treated as factors because of the missing data coding.

OpenMx documentation built on Aug. 21, 2025, 5:48 p.m.