Resize X11 Screen Size From Command Line
For reasons I needed to be able to resize my screen from the command line
xrandr --output $OUTPUT --mode 3840x2160
To get an $OUTPUT value, enter xrandr into your terminal with no commands and pick the name of the connected display.
The output should look something like this
Screen 0: minimum 320 x 200, current 3840 x 2160, maximum 16384 x 16384 DVI-D-1 disconnected (normal left inverted right x axis y axis) DP-1 connected primary 3840x2160+0+0 (normal left inverted right x axis y axis) 697mm x 392mm