local x `"||scatteri 0 -10 "-10" 0 10 "10" 0 20 "20","'
local x `"`x' mlabpos(6) mlabsize(*1.25)"'
local x `"`x' msymbol(none) mlabcolor(black)"'
local x `"`x'||scatteri 0 -10 "|" 0 10 "|" 0 20 "|" ,"'
local x `"`x' mlabpos(0) msymbol(none) mlabcolor(black)"'
local y `"||scatteri -3 0 "-3" 3 0 "3" 6 0 "6" 9 0 "9","'
local y `"`y' mlabpos(9) mlabsize(*1.25)"'
local y `"`y' msymbol(none) mlabcolor(black)"'
local y `"`y'||scatteri -3 0 "_" 3 0 "_" 6 0 "_" 9 0 "_","'
local y `"`y' mlabpos(0) msymbol(none) mlabcolor(black)"'
local ax "yli(0,lc(black) lw(thin)) xli(0,lc(black) lw(thin))"
local ax "`ax' ysc(off) xsc(off) leg(off)"
scatter y x,`ax'`x'`y' scheme(s2mono) graphr(fc(white)) yla(,nogrid)