*! NJC 1.1.0 8 Oct 2002
* NJC 1.0.0 1 Oct 2002 
* some ideas from -rsquare- P. Ender and R. von Eyden 1.1 2/12/02
* all tabs mapped to 4 spaces 
program define allpossible 
    version 7.0

    * process syntax 
    gettoken cmd 0 : 0
    syntax varlist(min=2 numeric ts) [aw fw iw pw] [if] [in] , /* 
    */ [ ECLASS(str) RCLASS(str) NPMAX(int -1) * Format(str)   /* 
    */ CELLWidth(int 12) Detail ] 
    
    marksample touse
    qui count if `touse' 
    if r(N) == 0 { 
        error 2000 
    }

    if "`eclass'`rclass'" == "" { 
        di as err "must specify at least one of eclass() or rclass()"
	exit 198 
    }	
    if "`rclass'" != "" { 
    	local nr : word count `rclass' 
	if `nr' < 2 { 
	    di as err "rclass() invalid"
	    exit 198 
	}
	tokenize `rclass' 
	local rprog "qui `1'" 
	mac shift 
	local rclass `*' 
    } 	

    tokenize `varlist'
    local response `1'
    macro shift
    local rest `*'
    local np : word count `rest'
    
    local npmax = cond(`npmax' > 0 , min(`npmax',`np', 6), `np') 
    local nfits = 0 
    forval i = 0 / `npmax' { 
        local nfits = `nfits' + comb(`np',`i') 
    }
    qui count 	
    if r(N) < `nfits' { 
        di as err "sorry: # of observations should be at least `nfits'"
        exit 198 
    }     

    * wire in response and apply any weights 
    local cmd "`cmd' `response'"
    if "`detail'" != "" {
        local cmd "noisily `cmd'"
    }    
    local etc "[`weight' `exp'] if `touse', `options'" 

    * main loop, except that we break out somewhere before repetition  
    qui while 1 { 

        * no predictors 
        `cmd' `etc' 
	foreach s of local eclass { 
            tempvar v`s' 
            gen double `v`s'' = e(`s') in 1 
            label var `v`s'' "`s'" 
            local results "`results'`v`s'' "
	} 	
	
	if "`rclass'" != "" { 
	    `rprog' 
	    foreach s of local rclass { 
	        tempvar v`s' 
	        gen double `v`s'' = r(`s') in 1 
	        label var `v`s'' "`s'" 
	        local results "`results'`v`s'' " 
	    }
        }	    
	    	
        tempvar predictors model 
        gen str6 `predictors' = "(none)" in 1 
        label var `predictors' "predictors" 
        gen byte `model' = _n 
        label var `model' "model"
             
        * one predictor
        local p = 1 
        qui forval i = 1 / `np' {
            `cmd' ``i'' `etc' 
            local p = `p' + 1 
            foreach s of local eclass { 
                replace `v`s'' = e(`s') in `p'
	    }
            if "`rclass'" != "" { 
	        `rprog' 
	        foreach s of local rclass { 
	            replace `v`s'' = r(`s') in `p' 
	        } 
	    }
            replace `predictors' = "`i'" in `p' 
        } 
             
        if `npmax' == 1 {
            continue, break 
        }    
      
        * two predictors
        local npm1 = `np' - 1 
        qui forval i = 1 / `npm1' {
            local j1 = `i' + 1
            forval j = `j1' / `np' {
                local p = `p' + 1 
                `cmd' ``i'' ``j'' `etc' 
                foreach s of local eclass { 
                    replace `v`s'' = e(`s') in `p'
                }     
		if "`rclass'" != "" { 
	            `rprog' 
	            foreach s of local rclass { 
	                replace `v`s'' = r(`s') in `p' 
	            } 
	        }
                replace `predictors' = "`i' `j'" in `p' 
            }     
        }

        if `npmax' == 2 {
            continue, break 
        }    
  
        * three predictors
        local npm2 = `np' - 2 
        qui forval i = 1 / `npm2' {
            local j1 = `i' + 1
            forval j = `j1' / `npm1' {
                local k1 = `j' + 1
                forval k = `k1' / `np' { 
                    local p = `p' + 1 
                    `cmd' ``i'' ``j'' ``k'' `etc'
                    foreach s of local eclass { 
                        replace `v`s'' = e(`s') in `p' 
                    }    
                    if "`rclass'" != "" { 
                        `rprog'                                            
                         foreach s of local rclass {  
                             replace `v`s'' = r(`s') in `p'         
			 }
                    }
                    replace `predictors' = "`i' `j' `k'" in `p' 
		}   
            }       		   
        }    
	
        if `npmax' == 3 {
            continue, break 
        }    

        * four predictors
        local npm3 = `np' - 3 
        qui forval i = 1 / `npm3' {
            local j1 = `i' + 1
            forval j = `j1' / `npm2' {
                local k1 = `j' + 1
                forval k = `k1' / `npm1' { 
                    local l1 = `k' + 1 
                    forval l = `l1' / `np' { 
                        local p = `p' + 1 
                        `cmd' ``i'' ``j'' ``k'' ``l'' `etc'
                        foreach s of local eclass { 
                            replace `v`s'' = e(`s') in `p' 
                        }
			if "`rclass'" != "" { 
			    `rprog' 
			    foreach s of local rclass { 
			        replace `v`s'' = r(`s') in `p' 
			    }
			}    
		        replace `predictors' = "`i' `j' `k' `l'" in `p' 
                    }
                }
            }     
        }

        if `npmax' == 4 {
            continue, break 
        }    

        * five predictors
        local npm4 = `np' - 4 
        qui forval i = 1 / `npm4' {
            local j1 = `i' + 1
            forval j = `j1' / `npm3' {
                local k1 = `j' + 1
                forval k = `k1' / `npm2' { 
                    local l1 = `k' + 1 
                    forval l = `l1' / `npm1' { 
                        local m1 = `l' + 1 
                        forval m = `m1' / `np' { 
                            local p = `p' + 1 
                            `cmd' ``i'' ``j'' ``k'' ``l'' ``m'' `etc'
                            foreach s of local eclass { 
                                replace `v`s'' = e(`s') in `p' 
                            }    
			    if "`rclass'" != "" { 
			        `rprog' 
				foreach s of local rclass { 
				    replace `v`s'' = r(`s') in `p' 
				}
			    }	
                            replace `predictors' = "`i' `j' `k' `l' `m'" in `p' 
                        }
                    }
                }     
            }     
        }
        
        if `npmax' == 5 {
            continue, break 
        }     
       
        * six predictors
        local npm5 = `np' - 5 
        quietly forval i = 1 / `npm5' {
            local j1 = `i' + 1
            forval j = `j1' / `npm4' {
                local k1 = `j' + 1
                forval k = `k1' / `npm3' { 
                    local l1 = `k' + 1 
                    forval l = `l1' / `npm2' { 
                        local m1 = `l' + 1 
                        forval m = `m1' / `npm1' { 
                            local n1 = `m' + 1  
                            forval n = `n1' / `np' { 
                                local p = `p' + 1 
                                `cmd' ``i'' ``j'' ``k'' ``l'' ``m'' ``n'' `etc'
                                foreach s of local eclass { 
                                    replace `v`s'' = e(`s') in `p' 
                                }     
				if "`rclass'" != "" { 
				    `rprog' 
				    foreach s of local rclass { 
				        replace `v`s'' = r(`s') in `p' 
				    }	
				}    
                                replace `predictors' = "`i' `j' `k' `l' `m' `n'" in `p' 
                            }
                        }
                    }     
                }     
            }
        }     

        if `npmax' == 6 {
            continue, break 
        }     
       
     } /* main loop */ 
     
     * table output 
     * integers mapped to strings to protect against decimal places 
     qui foreach v of local results { 
        capture assert `v' == int(`v') 
        if _rc == 0 { 
            tempvar v2 
            gen str1 `v2' = "" 
            replace `v2' = string(`v', "%9.0f") 
            _crcslbl `v2' `v' 
            local Results "`Results' `v2'" 
        } 
        else local Results "`Results' `v'" 
     } 
     
     if "`format'" == "" { 
        local format "%4.3f" 
     }


     tabdisp `model' in 1 / `p', c(`predictors' `Results') /* 
     */ format(`format') cellwidth(`cellwidth') 
     di 
     forval i = 1 / `np' { 
         di as res "  `i'" as text "{col 10}``i''" 
     }     

end