program define oer
    version 4.0

    preserve
    clear

    quietly{

        set obs 500
        gen x=.
        gen y=.
        gen xi=.
        gen xj=.}

    gph open
    gph pen 1


    local n=10
    local K=5
    local nK=`n'*`K'
    local incy=int(17000/(`K'-1))
    local incx=int(26000/(`K'-1))

    replace x=int((_n-1)/`K')+1
    replace y=invnorm(uniform())

    gph pen 2

    oneway y x
    local f1: display %5.2f _result(6)
    local nd1=_result(3)
    local nd2=_result(6)
    local pv1: display %5.3f fprob(`nd1',`nd2',`f1')
    gph text 1000 16000 0 0 n=`n', F=`f1', p-value=`pv1'

    gph pen 3

    local i=1
    while `i'<`K' {

        local j=`i'+1
        while `j'<=`K' {

            local i1=3000+(`i'-1)*`incy'
            local j1=3000+(`j'-2)*`incx'

            local ij1=10*`i'+`j'

            replace xi=.
            replace xj=.

            replace xi=y if x==`i'
            replace xj=y if x==`j'

            ttest xi=xj, unpaired

            local pv: display %4.3f tprob($S_5,$S_6)
            
            gph text `i1' `j1' 0 -1 `pv'
*            gph text `i1' `j1' 0 -1 `ij1'

            local j=`j'+1}

        local i=`i'+1}

    gph close
    restore

exit    
end