I found a straightforward answer to my question by reading the helpful information at Ubuntu Wiki: X - Input Coordinate Transformation.
These commands can be used to align rotations of the input devices and the display:
The first command rotates the display, where can be left, right, normal, or inverted:
xrandr -o <orientation>
remap the input device:
xinput set-prop '<device name>' 'Coordinate Transformation Matrix' <matrix-elements-rowwise>
The second command remaps the input device (that is, the touchpad or the the touchscreen) where
0 -1 1 1 0 0 0 0 1,
0 1 0 -1 0 1 0 0 1,
1 0 0 0 1 0 0 0 1, or
-1 0 1 0 -1 1 0 0 1; corresponding to the orientations above.
The names of the touchpad and touchscreen can be found with
xinput list and either can be disabled entirely with
xinput disable <device-name>. Subsequently,
xinput enable <device-name> will re-enable the input device.
In my case, and probably for others with a Yoga 13 (also on Yoga 2 Pro), the touchscreen is called
ELAN Touchscreen and the touchpad
SynPS/2 Synaptics TouchPad.
Thus, I put a short script in my home directory called
rotate-inverted.sh with the following content:
# This script rotates the screen and touchscreen input 180 degrees, disables the touchpad, and enables the virtual keyboard
xrandr -o inverted
xinput set-prop 'ELAN Touchscreen' 'Coordinate Transformation Matrix' -1 0 1 0 -1 1 0 0 1
xinput disable 'SynPS/2 Synaptics TouchPad'
Then I made the script executable with
chmod u+x rotate-inverted.sh
and assigned the command
~/rotate-inverted.sh to the keyboard shortcut Ctrl+Alt+I in
System Settings -> Keyboard.
After I logged out and logged back in, I was able to rotate the keyboard by pressing that shortcut.
I did the same type of thing for the other rotation positions, using the commands
xinput enable 'SynPS/2 TouchPad' and
killall onboard instead of
xinput disable 'SynPS/2 TouchPad' and
onboard & for
Some others on this thread have discussed assigning such scripts to the extra buttons on the
Yoga — such as the lock button — as well as automatically executing them upon changing the Yoga's position; but I was not sure how to do this.