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

twin_NA_dot {OpenMx} | R Documentation

## 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 http://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.

[Package OpenMx version 2.18.1 Index]