To pageup and pagedown without reserved lines

Question

When I scroll a whole page up by ctrl-f, and down by ctrl-b, vim reserves 2 lines, and repeats them both in the previous GUI window and the present one. But I expect it not to repeat lines, because now that the "turning" of pages is not a really "turning" but with a small shift, this makes me harder to visualize the new position which it is.

That is to say, if line 1 to line 30 is shown in present window, and to simplify matters suppose none is wrapped, then when I press ctrl-f, the subsequent GUI window will display line 29 to 58. But I want it to show line 31 to 60, and so on. What should I set in .vimrc?

Answer 1

I like to use the following:

nnoremap <c-f> z+
nnoremap <c-b> z^

Answer 2

It dawned on me that why do I not move page down and further scroll two lines, and same can be said on page up.

" Scroll a page with no repeated lines,
" while default shows two lines in both present and next window
nnoremap <C-f> <C-f><C-e><C-e>
nnoremap <C-b> <C-b><C-y><C-y>

I am finding myself on the right track of being a vim master.