window-resize

window-resize is a compiled Lisp function in `window.el'.

(window-resize WINDOW DELTA &optional HORIZONTAL IGNORE PIXELWISE)

Resize WINDOW vertically by DELTA lines.
WINDOW can be an arbitrary window and defaults to the selected
one. An attempt to resize the root window of a frame will raise
an error though.

DELTA a positive number means WINDOW shall be enlarged by DELTA
lines. DELTA negative means WINDOW shall be shrunk by -DELTA
lines.

Optional argument HORIZONTAL non-nil means resize WINDOW
horizontally by DELTA columns. In this case a positive DELTA
means enlarge WINDOW by DELTA columns. DELTA negative means
WINDOW shall be shrunk by -DELTA columns.

Optional argument IGNORE, if non-nil, means to ignore restraints
induced by fixed size windows or the values of the variables
`window-min-height' and `window-min-width'. The following values
have special meanings: `safe' means that in addition live windows
are allowed to get as small as `window-safe-min-height' lines and
`window-safe-min-width' columns. `preserved' means to ignore
only restrictions induced by `window-preserve-size'. If IGNORE
is a window, then ignore restrictions for that window only.

Optional argument PIXELWISE non-nil means resize WINDOW by DELTA
pixels.

This function resizes other windows proportionally and never
deletes any windows. If you want to move only the low (right)
edge of WINDOW consider using `adjust-window-trailing-edge'
instead.