Adding a custom resolution to uBuntu

script.sh

# create the mode using super user
$ sudo cvt 1366 768 60
[sudo] password for user: 
# 1368x768 59.88 Hz (CVT) hsync: 47.79 kHz; pclk: 85.25 MHz
Modeline "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync

# add the new mode from above commands output
$ sudo xrandr --newmode "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync

# Verify the monitor name
$ sudo xrandr -q
Screen 0: minimum 64 x 64, current 1280 x 1024, maximum 32766 x 32766
VGA-0 connected primary 1280x1024+0+0 0mm x 0mm
   800x600       60.00 +  60.00  
   2560x1600     60.00  
   2560x1440     60.00  
   2048x1536     60.00  
   1920x1600     60.00  
   1920x1080     60.00  
   1600x1200     60.00  
   1680x1050     60.00  
   1400x1050     60.00  
   1280x1024     60.00* 
   1024x768      60.00  
   640x480       60.00  
  1368x768_60.00 (0x296) 85.250MHz -HSync +VSync
        h: width  1368 start 1440 end 1576 total 1784 skew    0 clock  47.79KHz
        v: height  768 start  771 end  781 total  798           clock  59.88Hz

# set the new mode
$ sudo xrandr --addmode VGA-0 1368x768_60.00

xrandr.sh

#!/bin/bash
xrandr --newmode "1368x768_60.00"  85.86  1368 1440 1584 1800  768 769 772 795  -HSync +Vsync
xrandr --addmode VGA-0 1368x768_60.00
xrandr --output VGA-0 --mode 1368x768_60.00

## Above script should be added in startup application, so that screen resolution will be set automatically after startup.