script for adding standard modes to beamer for presenting on linux

add_modes_to_screen.sh

#!/bin/bash
# script for adding standard modes to beamer for presenting on linux
# use xrandr to find out screen name of external output port
# xrandr is in x11-xserver-utils package on debian/ubuntu
SCREENNAME=$1
if [ -z "$SCREENNAME" ]; then
   SCREENNAME=VGA-0
fi
function addmode() {
	xrandr --newmode `cvt $1 $2 |grep Modeline | sed -e 's/^Modeline //' | sed -e 's/\"//g'`
	xrandr --addmode $SCREENNAME $1x$2_60.00
}
addmode 1280 1024
addmode 1024 768
addmode 800 600
#addmode 1920 1200

I think the monitor has to be connected before running the script. You can check with xrandr command if it was able to add the forced modes.

Probably doesn't work for me anymore. I have Nvidia 310.44 driver version and it seems to have an incompatible xrandr version on Ubuntu 12.04.

There is another solution for Nvidia: http://askubuntu.com/questions/269901/ubuntu-12-10-cant-add-custom-resolution