grad life

Slow Alt-Tab behaviour in Linux Mint

2015-11-30T01:46:00.000-08:00

I personally do my best to avoid using the mouse. Thus, I use keyboard a lot, in particular I do 'Alt+Tab' to switch between applications (This doesn't work in Gnome3 and likes due to window grouping by default which is something totally ridiculous by the way). In new Linux Mint, Alt+Tab behaviour is noticeably slow (or sticky if you will). This can be overcome by turning off 'Preferences->Desktop Settings->Window-s -> Performance -> Use compositing"

2013-06-01T21:09:00.003-07:00

Bash to Python migration cheat sheet

Explanation	Bash	Python
change directory	cd	os.chdir(“/some/path/”)
print working directory	pwd	os.getdir()
print 4th line	sed -n “4p” somefile	linecache.getline(‘somefile’, 4)
list files	ls	subprocess.call(“ls”, shell=True)
remove/delete a file	rm somefile	subprocess.call(“rm somefile”, shell=True)
print 3rd column in a line	echo ‘this is a line’ \| awk ‘{ print $3 }’	“this is a line”.split()[3]
print 3rd column in a file	awk ‘{ print $3 }’ somefile	`for line in somefile line.split()[2]`

gitit as personal wiki

2013-01-21T19:31:00.002-08:00

These days I am playing around with gitit to see if it can make a good personal wiki. In fact, I am also curious how a personal wiki will improve my life. In order to turn gitit to a personal wiki I did the followings.

standard installation from ubuntu repository with apt-get
modify config file for minor things like if login required or session expiry time. In order to print a default config file see gitit man page or help file.
one needs a folder under which config file will be put along with the whole wiki. So I created a folder under home: ~/personal_wiki
the main thing which makes gitit a personal wiki is restricting it's access to the local host. So created the following command alias: alias pwiki='cd ~/personal-wiki/ ; gitit -f gitit.conf -l 127.0.0.1 -p 12000 & cd -'
I don't like using mouse; so I edit wiki page files (*.page) under ~/personal-wiki/wikidata/ with a simple text editor, then I commit it using another comman alias I created: alias commit='cd ~/personal-wiki/wikidata/ ; git commit -am "committed from command line"; cd -',
Finally, I preview the wiki withing a web browser by typing http://127.0.0.1:12000/ in adresbarr which is nothing but locahost ip and port number assigned to gitit.

set vlc as default media application in Ubuntu, Fedora (and probably other Linux distros) from command line

2012-04-03T16:59:00.000-07:00

Given that Totem is the default media player in Ubuntu, one can set VLC as default media player by replacing every instance of "totem.desktop" in the file /usr/share/applications/defaults.list by "vlc.desktop" as follows.
1. sudo cp /usr/share/applications/defaults.list /usr/share/applications/defaults.list.backup
2. sed 's/totem.desktop/vlc.desktop/g' /usr/share/applications/defaults.list > tempfile
3. sudo mv tempfile /usr/share/applications/defaults.list

References: VLC wiki page

efficient/productive computer user, keyboard shortcuts, tip #7

2011-11-27T19:59:00.001-08:00

for any program where editing involved, one can copy, paste, cut, save with Ctrl+S, Ctrl+V, Ctrl+X, and Ctrl+S respectively. Also Ctrl+O should bring open-file menu which is useful to know.

efficient/productive computer user, keyboard shortcuts, tip #6

2011-11-27T19:57:00.001-08:00

bring power menu to restart, suspend, hibernate, or power off your computer. Simply do Alt+Ctrl+Delete. Note that one can of course do this from a terminal as well.

efficient/productive computer user, keyboard shortcuts, tip #5

2011-11-27T19:55:00.001-08:00

Focus to or unfocus to desktop with OS-key+D or Alt+Ctrl+D

efficient/productive computer user, keyboard shortcuts, tip #4

2011-11-27T19:38:00.001-08:00

Focus to or un-focus from desktop with OSkey+D or Ctrl+Alt+D. Note OS-key or operating system key is the key with microsoft logo, or ubuntu logo, or tux on it.

efficient/productive computer user, keyboard shortcuts, tip #3

2011-11-27T00:01:00.001-08:00

Do Alt+Ctrl+Arrow to switch between workspaces.

efficient/productive computer user, keyboard shortcuts, tip #2

2011-11-26T23:55:00.000-08:00

Do Alt+F10 to resize/maximize a window.

efficient/productive computer user, keyboard shortcuts, tip #1

2011-11-26T23:37:00.000-08:00

Do Alt+Tab to switch between program windows quickly.

Netflix in Linux?

2011-03-23T11:56:00.000-07:00

Netflix is based on silverlight (codec?) thing which is designed for windows. Well, if they don't bother to support linux, then I will not bother to use netflix. Here is a good alternative to netflix: the Google Chrome app Cracle.

It is easy to use and install. Do the following:

Install Google Chrome: http://www.google.com/chrome/index.html
Install the Chrome App Crackle: https://chrome.google.com/webstore/detail/ibfamoapbmmmlknoopmmfofgladlinic
If you connect anywhere outside of USA, movie & TV show selection is not great. So consider getting an highspeed USA proxy. Foxyproxy is the best one for the job I think: http://getfoxyproxy.org/
After getting it, set it up withing the Google Chrome. Do: Google Chrome setup -> under the hood
Enjoy!

Advice for physics graduate students

2010-12-07T17:17:00.000-08:00

keyboard skills (VERY IMPORTANT)

learn how to touch type (it takes about 3 months or less with 3 hours per week of practice):see http://www.typingweb.com/ which has free & awesome touch typing courses
learn keyboard shortcut keys
remember you are not an average joe person in terms of computer using intensity and learning skills, so hunt-and-peck typing, or not using keyboard shortcuts is not good (ESPECIALLY IF YOU ARE A STUDENT IN COMPUTER SCIENCE AREA OR IF YOU DO PROGRAMMING FOR LIVING).

record and quantify how much you work

daily, weekly, yearly
on each course, assignment, chapter,...
on each research project, and sub projects
for paperwork, for research proposal,
using of a time-tracking software is advised (free ones should be enough for personal time-tracking)For example see gnotime

working a lot is working less

one cannot work a lot on a constant basis. It is ok if you do it before submitting your research proposal etc.
However, in general working for long hours constantly will decrease your motivation and efficiency thus it is not good for you in the long term. The point is not to work a lot but working efficiently.
Aim to work 40 hours at least and don't go beyond 50 hours weekly.
Make sure your efficiency (total time assigned to work/total time recorded) is in between 75% to 90%.

Read on personal efficiency: check out

Eat that Frog by Brian Tracy (google books / amazon)
Getting Things Done by David Allen ( google book / amazon)

HAVE A REGULAR SLEEP ORDER as you use your brain a lot as a graduate student.

exercise REGULARLY: invest in your body as much as you invest in your head!

24h-8h(sleep) = 16h usable time daily
7 x 16 = 112h weekly usable time
112-40 = 72h available for anything else than work
3h x 2 = 6hours of exercising weekly:
6h/72h = %8 of non-work time => NO EXCUSE for exercising !!!

meet regularly with you supervisor

be prepared and organized for this meeting:
have a list of questions
have a list of the things to discuss with your supervisor
have the supporting documents/files with you in an organized fashion

know beforehand how-much time you can take off yearly

discuss this with your supervisor

know your finances

know how much money you will have EXACTLY as of September 1st every year
know when and how-much you will get money, and you are supposed to pay tuition etc

save money

cook your own food (not always of course)
plan weekly your lunch (at least)
buy cold-pack and lunch bag, and bring food to office
every week check out grocery fliers online to see if your favorite foods are on sale. If so, buy tons of them. This can enable you save up to 50% on grocery bills.

socialize for a reasonable amount of time every week

Learn LaTeX

learn how to use citeulike for bibliography purposes

put ALL of your research/grad studies activity in a single LaTex file

include every individual activity as a separate file*
turn on and off files, by commenting/uncommenting \includefile command, depending on your daily needs

learn THE VERY BASICs of:

a low level language: Fortran/C/C++
bash scripting: grep, sed, awk
Linux operating system
symbolic/numeric math software:

Wxmaxima
Mathematica
Maple
Octave
Matlab

5. plotting software:

xmgrace
gnuplot

computer skills

learn how to automate things by writing scripts. for example don't do the followings by hand: compile a code with specific linked libs and options; run the code for input 1, .... input 20; for each output plot a data to GUI, generate .eps files, and move them to a certain folder; put these .eps files in a latex document; compare each output with another output, ...etc.
don't be afraid of computers/computer problem as you are a graduate student who is expected to able to solve problems and who is expected to have good learning skills. So, learn from every problem that you experience, if someone solves a problem for you, write up a howto document right away as you will not remember the solution even next day and as you don't want to bug that person again.
Use Google and online forums (a lot) to seek for guides/howtos/solutions for computer tricks/problems.

How to submit I-94 form to border officers at Toronto Pearson Airport

2010-12-07T16:45:00.000-08:00

I live in Canada, and once in a while I cross the border. When I do that, I get a form/piece of paper called I-94 which is a record of entry. One can either surrender this thing right away on the way back or can use it until the expiry date. I in general do the latter one, and recently I have realized that one can surrender I-94 to border officials at Toronto Pearson airport as opposed to surrendering it at a land border which might be less convenient from transportation and cost point of view.

Basically, one can surrender the I-94 form to a canadian border officer. So, do the following:

1. Go to Terminal 3, pearson airport
2. Go to "Canada border agency"/customs information office located at level 1. See the image below where the location of this office is indicated with an arrow:

For a full Terminal 3 map, check out: http://www.gtaa.com/en/travellers/airport_information/terminal_info/

Note this should work for any airport which has international flights.

I hope this post will be useful for many people.

Ubuntu 10.10 on Sony Vaio Netbook (VPCM111AX)

2010-12-02T23:16:00.000-08:00

I just recently purchased a Sony Vaio netbook (VPCM111AX). Initially, I was hesitant to buy a netbook since I wasn't sure if its computational power would be sufficient for me. It turns out it is not really true that you cannot do more than a few things at a time. I so far haven't experienced any slowness due to opening many applications. To be clear, I am not an average Joe laptop user, thus the apps that I use go way beyond internet browsers.

I think if one doesn't do hard-core gaming or hard-core numerical simulations, netbook is a perfect match for your daily computing needs. Also I find the screen size is really perfect for me. After using this netbook, I consider any laptop bigger than 12" screen as an unmobile piece of product.

Netbook thing is really practical, I don't really think twice if my backpack will be heavy etc. It is substantially lighter than my previous 15" laptop which gave me serious shoulder problems when I go to conferences etc.

Speaking of Ubuntu, I have the 10.10 Maverick Meerkat version installed on my netbook. Everything works out of the box: keyboard, function keys, power management, wireless, mic (int & ext), bluetooth, graphics (vga and associated function key works out of the box), and suspend mode. Though I haven't tested the memory card reader yet. Additionally, battery lasts 4.5 hours with wireless is on half the time.

One reason why I post this is that this netbook is not listed in the ubuntu compatible netbook list. So I took some chances however I knew before the purchasing the netbook that linux works nicely on Sony laptops. I hope some others who want to purchase this netbook and use withubuntu will find this post useful

Save more than 10% battery life with adblock

2010-11-13T19:52:00.000-08:00

As I mentioned before, I bought a netbook recently. Naturally I was experimenting with ways of getting the most out of the built-in battery. I just realized that blocking flash based moving ads on websites can enable you to save more than 10% battery life.

Here is the main result.
the power consumption of the netbook is:

11.2 Watts before blocking, and
9.5 Watts after.

So, if you are on the go and doing web browsing, and would like save some battery power, block ads.

Notes:
1. link to adblock: http://addons.mozilla.org/en-US/firefox/addon/1865/
2. in order to see power stats, use the linux command "gnome-power-statistics".

how to switch/reassign keyboard keys in linux / ubuntu / fedora

2010-11-12T16:29:00.000-08:00

I recently bought a netbook which came with a good size keyboard. However, due to the space constraint, the netbook producer, turns out, combined the Page-up and Home, and Page-Down and End keys. Well, as a touch typist and a programmer, I often use Home and End keys, and it is certainly a pain to be able to access them only via a Function key like Fn+Page-up=Home. So I did some googling, and here is the result.

1. Install Xmodmap
in ubuntu do: sudo apt-get install xmodmap
in fedora do: sudo yum install xmodmap

2. get the "keysym" name of the keys using xev
keysym of "home" key is "Home"
xev
press the Home key
KeyRelease event, serial 33, synthetic NO, window 0x1800001,
root 0xaa, subw 0x0, time 3028114, (288,433), root:(289,515),
state 0x0, keycode 110 (keysym 0xff50, Home), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False

via xev: keysym of "Page up" key is "Prior"
xev
press the Page up key
KeyRelease event, serial 33, synthetic NO, window 0x1800001,
root 0xaa, subw 0x0, time 2825051, (322,253), root:(323,335),
state 0x0, keycode 112 (keysym 0xff55, Prior), same_screen YES,
XLookupString gives 0 bytes:
XFilterEvent returns: False

4. switch keys by doing two assignments
xmodmap -e "keysym Home = Prior" -e "keysym Prior = Home"

Crazy pace of decreasing per GB cost of hard-disk data storage

2009-12-24T11:12:00.000-08:00

At the year 2000, the cost of hard-disk storage was ~$20 per GB. A quick calculation gives that a TeraByte disk that we can purchase for ~$100 nowadays would cost ~$20,000 about 10 years ago. Isn't this mind blowing?
See http://www.alts.net/ns1625/winchest.html for the hard-drive prices by year.

A "must read" book on sustainable energy.

2009-12-24T09:26:00.000-08:00

Sustainable
Energy - without the hot air

by David MacKay

Developed countries heavily rely on fossil fuels as an energy source which are expected to be consumed up in 50 years or so. Additionally, fossil fuels are the main cause of global warming as you might already know. In the not too distant future, we have to get off the fossil fuels. Well, how can we do that without compromising in our living-quality? David MacKay gives a quite coherent answer to this question in his book where he processes and summarizes immense amount of information on the energy subject. A striking feature of this book is that it is accessible for the average Joe.
This book is available online for free at: http://www.withouthotair.com/

here is a guest blogger from wordpress: QuantumBee writes on quantum entanglement

2009-12-23T17:45:00.000-08:00

Quantum entanglement is one of the hot topics of modern physics. QuantumBee gives a brief account of this topic which is accessible for the average Joe.
http://quantumbee.wordpress.com/

next "wave" on internet music: GrooveShark

2009-12-22T18:29:00.000-08:00

It is literally possible to stream every song on earth to your computer via "www.grooveshark.com". Note that this website is legal, and currently has agreements with big music companies. I guess they are planning to make money via ads displayed on the website or you pay < $10 to avoid these.

How to create a foiltex pdf presentation?

2009-02-25T14:48:00.000-08:00

STEPS
1. Include the following lines in the main tex file:

\documentclass[landscape,dvips]{foils}
\usepackage{graphicx} % This may not be necessary
\usepackage[pdftex]{geometry}
\geometry{headsep=2.0em,hscale=0.80}

2. compile the *.tex file with the latex command:
latex filename.tex
3. view the file with xdvi:
xdvi -paper a4r filename.dvi

4. convert the dvi file to pdf:
dvipdf filename.dvi