Twin biometric data (Practice cleaning: "." for missing data, wrong data types etc.)
Data set used in some of OpenMx's examples.
data("twin_NA_dot")A data frame with 3808 observations on the following variables.
famFamily ID variable
ageAge of the twin pair. Range: 17 to 88, coded as factor
zygInteger codes for zygosity and gender combinations
partCohort
wt1Weight in kilograms for twin 1 (this and following have "." embedded as NA...)
wt2Weight in kilograms for twin 2
ht1Height in meters for twin 1
ht2Height in meters for twin 2
htwt1Product of ht and wt for twin 1
htwt2Product of ht and wt for twin 2
bmi1Body Mass Index for twin 1
bmi2Body Mass Index for twin 2
Same as myTwinData but has . as the missing data value instead of NA.
Timothy Bates
The OpenMx User's guide can be found at http://openmx.ssri.psu.edu/documentation.
data(twin_NA_dot) summary(twin_NA_dot) # Note that all variables are treated as factors because of the missing data coding.
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