Hello teacher
I have a problem need to help
How to use "rangestat"
why it always arise
"no result for all obs: reg Rpret smb hml rmrf
varlist required"

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str6 yymm double(smb hml market_ret rf rmrf) long cno str18 company float Rpret
"200701"  3.12479616136284 -.946560127760525 -1.57332842382777             .145 -1.71832842382777 4413 "飛寶企業     " 175.2998
"200702" -.054768649075388  .668350900802062  2.71531150528581             .145  2.57031150528581 1605 "華新         "     2.8612
"200703"  4.79465078163792 -4.62623103090644  .218138426301922             .145 .0731384263019219 5607 "遠雄港       "   29.6861
"200704"  2.63776116616875  2.01197895130672 -.236541909574656            .1475 -.384041909574656 2340 "光磊         "   -12.7996
"200705"  3.20792829493895 -3.62334403288276  3.59083392641476            .1475  3.44333392641476 4426 "利勤         "    -6.6571
"200706"  .597232055202316 -.562965221638504  9.15066870121975 .164166666666667  8.98650203455309 1709 "和益         "     6.6122
"200707"   3.6827611537904 -7.49238259121798  5.39649256274856 .164166666666667  5.23232589608189 5475 "德宏         "     -1.337
"200708" -2.58833642885942  1.43233697213802 -4.31033144931462 .164166666666667 -4.47449811598128 1454 "台富         "     -.9675
"200709" -1.63550330294556  1.82901073387499   5.0428621569314 .169166666666667  4.87369549026473 2481 "強茂         "      6.112
"200710" -2.65628432387894 -1.97051039564794  1.57116835135739 .169166666666667  1.40200168469072 3042 "晶技         "   -12.6199
end

gen yq = date(yymm,"YM")
format yq %tm
replace yq = mofd(yq)
encode company, gen(id)

rangestat (reg) Rpret smb hml rmrf, interval(yq 0 0) by(id)