{smcl} {* *! version 1.2.1 07mar2013}{...} {findalias asfradohelp}{...} {vieweralsosee "" "--"}{...} {vieweralsosee "[R] help" "help help"}{...} {viewerjumpto "Syntax" "examplehelpfile##syntax"}{...} {viewerjumpto "Description" "examplehelpfile##description"}{...} {viewerjumpto "Options" "examplehelpfile##options"}{...} {viewerjumpto "Remarks" "examplehelpfile##remarks"}{...} {viewerjumpto "Examples" "examplehelpfile##examples"}{...} {title:Title} {phang} {bf:regsets} {hline 2} Generates complete sets of variables for regression analysis {marker syntax}{...} {title:Syntax} {phang} {bf:regsets :} [{varlist}] {marker description}{...} {title:Description} {pstd} {cmd:regsets} uses combinatory calculus to calculate the number of combinations without repetitions of the set of variables listed in {varlist}. For example, a set of 3 variables A, B and C can generate 3 combinations of 1 variable (A,B,C), 3 combinations of 2 variables (AB,BC,AC) and 1 combination of 3 variables(ABC) for a total of 7 combinations. The formula used to calculate the number of possible combinations is 2^(n+1)-1 where n is the number of variables. This is a shortcut to quickly visualize all possible sets of regressors that can be used from an initial set of variables. {marker remarks}{...} {title:Remarks} {pstd} {cmd:regsets} is an input to {cmd:regall}. Use '&' to combine variables and tell the program to treat these variables as one. {marker author}{...} {title:Author} {pstd} Paolo Verme, World Bank, pverme@worldbank.org {marker aknowledgments}{...} {title:Aknowledgments} {pstd} The author is grateful to Aziz Atamanov, Olivier Dupriez and Philippe Van Kerm for useful suggestions. {marker examples}{...} {title:Examples} {phang}{cmd: sysuse auto, clear}{p_end} {phang}{cmd: regsets: headroom price trunk}{p_end} {phang}{cmd: regsets: headroom weight length&turn}{p_end}