Transpose melody piano staff

Got a melody on the upper staff and want to copie the melody to the lower staff in octaves
Is there a easy method for doing this ?

There’s a useful Edit > Paste Special > Duplicate to staff below function, to which many of us have assigned a custom keyboard shortcut. You could also just copy and paste and then use Ctrl/Cmd-Alt/Opt-Down.

If you mean you want to add the same melody to the bottom staff but an octave below the top staff: select the notes, hold down Alt/Opt and click the bottom staff directly below the beginning of the selection (i.e. where the melody starts). This copies your selected material to the position of the cursor when you click. Then press Ctrl/Cmd-Alt/Opt-Down arrow to transpose it down an octave. (On Windows, that’s Ctrl-Alt-Down arrow, on Mac it’s Cmd-Opt-Down arrow)

You could also select the top staff melody, press Shift-I for the add intervals popover, enter “-8” (for an octave below), press Return, then press Alt-M to move the added notes to the staff below. (They should remain selected after you add them using the popover.)

To make a keyboard shortcut could be handy for harmony doubling and octave doubling : Make a copy of the melody is no problem( in this case clicking on the bottom staff makes not that the melody is placed on the bottom staff, because it was above the top stat of the melody) , so i tranpose the melody lower with the down arrow.

There is no indication on the bottom staff where the start octave note will be ,so i must deduct this from reference notes on the staffs
It not advisable to get too much counting with the notepositions on the screen for me : i will print out a staff with the note names on to make working with the intervals easier ( yes much easier)

Jan, ik begrijp je probleem niet. De toetscombinaties voor bijv. oktaafverdubbelingen en kopiëren naar de onderste balk worden ongeveer 10 cm hierboven met engelengeduld aan je uitgelegd, en die had je ook uit allerlei andere documentatie kunnen halen. Begrijp ik dat je zou willen dat Dorico van tevoren laat zien waar geoktaveerde noten in de onderste balk terecht gaan komen? Waarom? Probeer het, dan zie je het vanzelf. Als het je niet bevalt doe je Ctrl-Z (Cmd-Z op Mac) en probeer je wat anders.