This is a help function to count the number of individuals in an object read in with genDataRead (or loaded with genDataLoad).
nindiv(data.in, design = "triad")
How many individuals (integer).
The data read in by genDataRead.
The design used in the study - choose from:
triad (default) - data includes genotypes of mother, father and child;
cc - classical case-control;
cc.triad - hybrid design: triads with cases and controls