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 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.
```

[Package

*OpenMx*version 2.21.11 Index]