To have a wide equation or content in a two-column document: LaTex and Lyx

% in header 
% in document
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Appendix decoration

Add the following lines at the end of LaTex or Lyx file

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How to include bibliography in ToC of Latex/Lyx

Add the following line in your LaTex/Lyx header.


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MATLAB plot, line width

Object-oriented way

l = plot(x1,y1,x2,y2); 
l(1).LineWidth = 3; % set line width of 3 for the first line (x1,y1) 
l(2).LineWidth = 6;

or typical way

h = plot(x1,y1,x2,y2);
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To restart figure and table numbers in Appendix with correct link

In the LaTex/Lyx header, add the following package:


Where the Appendix start, add the following script:

% If figure/table numbers follow thos of the previous section, add: 

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Emacs word wrap and replace space by dash

(defun ttl ()
"To apply word wrap in an entire document file"

;; to replace " " between words by dash "-".
(fset 's2d (kmacro-lambda-form [? ?r ? return ?- return ?!] 0 "%d"))

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How to obtain CPU and memory information of Ubuntu system

cat /proc/cpuinfo | grep "model name"   

Command line

cat /proc/meminfo
free -m
vmstat -s



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How to use dolphin as a file manager to open a download directory

Open up /usr/share/applications/defaults.list and change line




Source URL:

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How to screen capture every 3 seconds

while true
   scrot -d 3 -u "${prefix}_$(date +%y%m%d_%H%M%S)".png

Usage : scrot [OPTIONS]… [FILE]
Where FILE is the target file for the screenshot.
If FILE is not specified, a date-stamped file will be dropped in the
current directory.
See man scrot for more details
-h, –help display this help and exit
-v, –version output version information and exit
-b, –border When selecting a window, grab wm border too
-c, –count show a countdown before taking the shot
-d, –delay NUM wait NUM seconds before taking a shot
-e, –exec APP run APP on the resulting screenshot
-q, –quality NUM Image quality (1-100) high value means high size, low compression. Default: 75. For lossless compression formats, like png,
low quality means high compression.
-m, –multidisp For multiple heads, grab shot from each
and join them together.
-s, –select interactively choose a window or rectangle with the mouse
-u, –focused use the currently focused window
-t, –thumb NUM generate thumbnail too. NUM is the percentage of the original size for the thumbnail to be, or the geometry in percent, e.g. 50×60 or 80×20.
-z, –silent Prevent beeping

Both the –exec and filename parameters can take format specifiers
that are expanded by scrot when encountered.
There are two types of format specifier. Characters preceded by a ‘%’
are interpreted by strftime(2). See man strftime for examples.
These options may be used to refer to the current date and time.
The second kind are internal to scrot and are prefixed by ‘$’
The following specifiers are recognised:
$f image path/filename (ignored when used in the filename)
$m thumbnail path/filename
$n image name (ignored when used in the filename)
$s image size (bytes) (ignored when used in the filename)
$p image pixel size
$w image width
$h image height
$t image format
$$ prints a literal ‘$’
\n prints a newline (ignored when used in the filename)
scrot ‘%Y-%m-%d_$wx$h_scrot.png’ -e ‘mv $f ~/images/shots/’
Creates a file called something like 2000-10-30_2560x1024_scrot.png
and moves it to your images directory.

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How to search specific email message in Thunderbird

Install thunerlink at

$ thunderbird -thunderlink thunderlink://messageid=<message id>

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