I use Octave with gnuplot under Windows.
I can zoom in using the right mouse button. But how can I zoom out from the UI?
Answer
I found this post on Nabble. Pressing p takes you to the previous zoom level, n to the next level, and u unzooms. I pressed h in a gnuplot window outside of Octave and got this command list:
2x<B1> print coordinates to clipboard using `clipboardformat`
(see keys '3', '4')
<B2> annotate the graph using `mouseformat` (see keys '1', '2')
or draw labels if `set mouse labels is on`
<Ctrl-B2> remove label close to pointer if `set mouse labels` is on
<B3> mark zoom region (only for 2d-plots and maps).
<B1-Motion> change view (rotation). Use <ctrl> to rotate the axes only.
<B2-Motion> change view (scaling). Use <ctrl> to scale the axes only.
<Shift-B2-Motion> vertical motion -- change xyplane
Space raise gnuplot console window
q * close this plot window
a `builtin-autoscale` (set autoscale keepfix; replot)
b `builtin-toggle-border`
e `builtin-replot`
g `builtin-toggle-grid`
h `builtin-help`
l `builtin-toggle-log` y logscale for plots, z and cb for splots
L `builtin-nearest-log` toggle logscale of axis nearest cursor
m `builtin-toggle-mouse`
r `builtin-toggle-ruler`
1 `builtin-decrement-mousemode`
2 `builtin-increment-mousemode`
3 `builtin-decrement-clipboardmode`
4 `builtin-increment-clipboardmode`
5 `builtin-toggle-polardistance`
6 `builtin-toggle-verbose`
7 `builtin-toggle-ratio`
n `builtin-zoom-next` go to next zoom in the zoom stack
p `builtin-zoom-previous` go to previous zoom in the zoom stack
u `builtin-unzoom`
Right `builtin-rotate-right` only for splots; <shift> increases amount
Up `builtin-rotate-up` only for splots; <shift> increases amount
Left `builtin-rotate-left` only for splots; <shift> increases amount
Down `builtin-rotate-down` only for splots; <shift> increases amount
Escape `builtin-cancel-zoom` cancel zoom region
* indicates this key is active from all plot windows