{smcl} {* 13Apr2006}{...} {hline} help for {hi:pairdata} {hline} {title:Create paired datasets from individual-per-row data} Basic syntax: {p 8 21 2}{cmd:pairdata} {it:varlist} [{cmd:if} {it:exp}]{cmd:,} {cmdab:ind:ividual(}{it:varname}{cmd:)} {cmdab:fam:ily(}{it:varname}{cmd:)} [{cmdab:con:stant(}{it:varlist}{cmd:)}] {title:Description} {p 4 4 2} {cmd:pairdata} converts individual-per-row data to single and double-entered paired data. {center: (original) } {center:fam ind var cons} {center:{hline 31}} {center: 1 1 44 P} {center: 1 2 45 P} {center: 1 3 46 P} {center: 2 1 47 Q} {center: 2 2 48 Q} {center: (single) } {center:fam cons ind_1 ind_2 var1_1 var1_2} {center:{hline 51}} {center: 1 P 1 2 44 45} {center: 1 P 1 3 44 46} {center: 1 P 2 3 45 46} {center: 2 Q 1 2 47 48} {center: (double) } {center:fam cons ind_1 ind_2 var1_1 var1_2} {center:{hline 51}} {center: 1 P 1 2 44 45} {center: 1 P 1 3 44 46} {center: 1 P 2 3 45 46} {center: 1 P 2 1 45 44} {center: 1 P 3 1 46 44} {center: 1 P 3 2 46 45} {center: 2 Q 1 2 47 48} {center: 2 Q 2 1 48 47} {p 4 4 2} {cmd:pairdata} creates three paired datasets based on pair combinations within familyID: {p 8 12} double.dta: double entered file with all possible pair combinations {p_end} {p 8 12} single.dta: single entered file with unique pair combinations {p_end} {p 8 12} singlerand.dta: single entered file with unique pair combinations controlling for any type of order effect {p_end} {p 4 4 2} {cmd:pairdata} also generates two new variables for each of the three files: {p 8 12} famcount: the number of members in each family. {p_end} {p 8 12} nsibpair: a count of the number of pairs formed from each family. {p_end} {title:Required Options} {p 4 8 2} {cmdab:ind:ividual(}{it:varname}{cmd:)} Specify individualID variable, this must be numeric and unique within familyID. {p 4 8 2} {cmdab:fam:ily(}{it:varname}{cmd:)} Specify familyID variable, this must be numeric and unique between families. {title:Other Option} {p 4 8 2} {cmdab:con:stant(}{it:varname}{cmd:)} Specify constant variables, i.e. family specific variables. {title:Examples} {cmd:. pairdata var1 var2, ind(individualID) fam(familyID)} {cmd:. pairdata var1-var2, ind(individualid) fam(familyid) con(famtype)} {title:Author} {p 8 12}Richard J Williamson. {p_end} {p 8 12}Social Genetic Developmental Psychiatry Research Centre, {p_end} {p 8 12}Institute of Psychiatry, {p_end} {p 8 12}Kings College London. {p_end} {p 8 12}U.K. {p_end} {p 8 12}richard.williamson@iop.kcl.ac.uk {p_end}