program define drpoint
    version 4.0

    local x      = `1'
    local y      = `2'
    local sz     = `3'
    local sm     = `4'


    local x1 = int($AX * `x' + $BX)
    local y1 = int($AY * `y' + $BY)

    gph point `y1' `x1' `sz' `sm'

end