LaTeX Tips and Tricks

• Interactively setting a variable

  Add similar lines before \documentclass

  \typeout{Please enter a value for var}
  \typein{\var}{var=}
  

• Including pages from other PDF documents

  \usepackage{pdfpages}
  ........
  \begin{document}
  \includepdfset{pages=-}
  \includepdf{cv.pdf}
  \includepdf{pubication1.pdf}
  \includepdf{pubication2.pdf}
  

  pdfpages provides lot of flexibility with selective
  inclusion of pages, landscape mode, etc.

• Adding directories to package search path
  (from Paul Jolly)

  % The trailing colon indicates the standard search
  % path should be appended to the user specified
  % TEXINPUT variable
  
  % Paths are ':' separated
  export TEXINPUTS=".:~/path/to/add:"
  export TEXINPUTS=".:~/path/to/add:/second/path/to/add:"
  
  % Trailing '/' for directories is optional
  export TEXINPUTS=".:~/path/to/add/:"
  
  % double trailing slash indicates this directory is
  % to be search recursively
  export TEXINPUTS=".:~/path/to/add//:"
  

• Input files with relative path

  \input and \include are well known commands for
  preparing larger documents from smaller files. However, if
  these smaller sections of text are organized within a
  directory with its own \input, \include,
  \includegrapics, etc., \input won’t work. For such
  cases, LaTeX package import can help.

  \usepackage{import}
  \import*{/play/act1/}{act.tex}
  

  On encountering \input{scene1.tex} in act.tex, LaTeX
  will now search for scene1.tex in /play/act1/ in addition to
  the local directory

• Embedding fonts

  Give -dPDFSETTINGS=/prepress option to ps2pdf and
  verify final output with pdffonts

  In my case, gnuplot was the culprit that was not
  embedding the fonts in figures. A more effective but
  time-consuming way of correcting it is to specify tex
  font file to gnuplot as specified
  here
  or in more details here

Firefox Tips and Tricks

• Editing textarea with your favorite editor

  Very often one would prefer to write in a text area on the web using
  ones favorite editor. For example, if you use Gmail you might like to have
  the power of vim or emacs while composing mails. You can do that with
  It’s All Text that displays an edit button that pops up your
  favorite editor.

  • Getting it to work with cygwin and vim
    Create a file gvim.bat (in notepad) with the following text

    @echo off
    C:\cygwin\bin\run.exe -p /usr/X11R6/bin gvim -display
    127.0.0.1:0.0 %*
    

    set editor to C:\path_to_gvim.bat

• Quickly accessing commonly used bookmarks

  Use keyword bookmarking. Access any bookmark’s property ( Ctrl+Shift+B
  and then the bookmark you are interested in or right click toolbar
  bookmarks and then Properties) and set keyword for any character or
  sequence of characters. Now you can access this bookmark by pressing
  Alt+D or Ctrl+L (to jump to the address bar) character [Enter].
  Further customization with string substitution is possible. However,
  using keyword with bookmarklet is still an issue.
  More Information

Vim Tips and Tricks

• In order to replace a text in a set of files

  :args <list of files>
  :argdo %s/search/replace/ |w
  

• Adding simple syntax highlighting on the fly

  Using the syntax command, syntax rules can be added to vim
  to improve readability of the file. While there are many
  options available (see :h syntax), I found the syntax
region option fit for my use. Say we want to turn every
  line starting with ** into a different color. We can do
  that using command

  :syntax region Nontext start="^\*\*" end="$"
  

  The above command says that any line starting with **
  should be displayed in the color pattern as defined by the
  group-name Nontext. A syntax region description like
  above needs to specify a start pattern (a regex) and an
  end pattern (another regex). In the example above the
  start pattern is ^**, i.e., any line starting with **
  and the end pattern is $, i.e., end of line. (since *
  needs to be escaped in vim, a regex ^** becomes ^\*\*
  in the above example). Vim has some standard color names
  define that can be used to define the appearance of
  selected region. Try :hi to list all the group-name and
  how they would look on the current terminal. This example
  uses on of the standard group-name define as Nontext.

  Recently, I had to submit some reviews and I choose to
  submit it using a text file (reviews.txt) provided to
  me. The file has a large number of section in the
  following format:

  @paper: xyz
  @type: paper
  \*\* SOME TITLE:
  @T1
  <replace with one or more lines of review text>
  @@
  \*\* SOME TITLE:
  @T2
  <replace with one or more lines of review text>
  @@
  

  In order to quickly identify places that I need to add
  text, I added the following lines to a file (hi.vim)

  syntax region Nontext start="^\*\*" end="$"
  syntax region Question start="^@" end="$"
  syntax region Diffchange start="^-" end="$"
  

  and edited by file by opening it as

  gvim -S hi.vim review.txt
  

  Try it and the usefulness of these line will be apparent.

SVN Tips and Tricks

• Avoid typing long svn commands by defining appropriate function in your
  .bashrc

  export SVN_PATH="svn+ssh://path_to_svn/trunk"
  function sl () { svn ls ${SVN_PATH:?"SVN_PATH is not unset
  or empty"}/${1:?"Insufficient arguments"}}
  

  You can now list trunk/projects as

  sl projects
  

Bash Tips and Tricks

• Using CDPATH can save a lot of keystrokes. CDPATH is to cd what
  PATH is to command completion. For example,

  export CDPATH=.:/home/joe/projects:
  

  will allow you to cd into a directory /home/joe/projects/wordpress from
  any directory using

  cd wordpress
  

• $'STRING' can help you print anything you wish. In STRING escape
  ' by \'

  $> echo $'foo\'bar'
  foo'bar
  

• Check variables as

  ${VAR_NAME?"VAR_NAME is not defined"}
  ${VAR_NAME:?"VAR_NAME is not defined or empty"}
  

• bash_completion allows you to go beyond command completion to listing
  options available for the command. For example, on the latest version of
  unbuntu (8.04) add source /etc/bash_completion to your .bashrc. If
  subversion is installed on your machine then $> svn <tab> will
  list all possible options in svn as:

  add        co         -h         log        pedit      proplist   rm
  annotate   commit     help       ls         pget       propset    status
  blame      copy       --help     merge      plist      pset       switch
  cat        cp         import     mkdir      praise     remove     unlock
  checkout   delete     info       move       propdel    rename     update
  ci         diff       list       mv         propedit   resolved   --version
  cleanup    export     lock       pdel       propget    revert
  

  It supports many other commands. It’s auto-completion of
  directories on a remote server for scp is really useful.

• Prevent annoying ssh disconnection by

  alias ssh='ssh -o TCPKeepAlive=no -o ServerAliveInterval=15
  -o ServerAliveCountMax=10'
  

  Alternatively, you can set these options in your ssh_config ($>
locate ssh_config) file. You can also try

  alias ssh='ssh -o TCPKeepAlive=yes
  

  But it didn’t work for me. For further information and for putty
  settings see

  http://drupal.star.bnl.gov/STAR/comp/sofi/facility-access/ssh-stable-con

• Bash has some lesser know command that provides exactly what you might
  sometimes be looking for. A quick read of info coreutils is recommended.
  Few such commands are

  • pr can help you paginate or columnate text. For example,

    pr -2 <filename>
    

    will generate a two column output of the text with page boundaries
    delimited with page headers and footers

  • paste to concatenate files vertically

  • tac to concatenate files in reverse order.

    tac <filename>
    

    to print file <filename> in reverse order

  • Get a quick directory overview to a depth of <n>

    tree -L <n> <dir_name>
    

Online Lectures, Talks, etc.

• Video Lectures
  Thanks Abhishek

• Research Channel
  Thanks Nilesh

• Parc Talks

• Tech Talks at Google

What Google Needs

Google Search

• Ability to search an image similar to a given image.
  • Today, we enter text and expect Google to list all the sites containing that text. A natural extension to this would be to upload an image and get all websites having a similar image. Applications could range from (a) finding all websites that use a trademark image to (b) Finding details about a personality (place, paintings, etc.) by her/his (its) picture. (I recently (Feb. 2009) attended a talk by Kilian Weinberger from Yahoo Research on machine learning techniques to accomplish it.)
• Purging invalid links and associated cache
  • An option, say “Check link validation”, in Google search to let users inform Google that a site is no more valid. Google says it’s crawler would detect it but I have seen invalid links (and its cached copy) on Google for months.

(Note: Many, including Google, have compiled features list, but I have compiled here the ones I didn’t find on (at least) the ones I browsed.)

Travel Tips

Buying Tickets

A list of sites to search for an air ticket

• Farecast now Bing Travel
• CheapTickets
• FareCompare
• Kayak
• OAG
• FareCompare
• AirlineConsolidator
• cFares
• TripAdvisor
  Includes a fee estimator for baggage, on-board meals, etc.

While waiting for the flight

• Price Check
  • Yapta
    After purchasing a ticket mail it to flights@yapta.com and yapta
    will tell you whenever the prices go down to claim a credit.
• Seat Selection and Trip Planning
  • SeatGuru
    Get reviews to pick us the best available seats.
  • checkmein
    Paid service, currently restricted to few airlines, that checks in
    as per user’s preferences when online check in begins.
  • TripIt
    Mail your complete itinerary to Tripit which compiles it in a
    single file with addition information that you might require
    during the trip.
• Flight Status
  • FlightStatus
  • Flight Delay Information
  • Flight Aware
  • FlightCaster
    Predicts flight delays.
• Miscellaneous
  • FlyingFees
    Find out about baggage policies and fees for various airlines.

Refunds

• MissRefund
  Get something back even from a non-refundable ticket. Read more
• Payoffs on overbooked flights

India Specific

Travel Agent

• Shalom Trip

Domestic (India)

• Make My Trip

Recommendations for Elevator Design

Feature recommendations

• The open door switch should be color coded (so that next time we
  want to help someone we can find the switch to press before it’s too
  late.)
• A switch to deselect a floor if one accidentally selected it.

Next Generation Travel Sites

Current Solution

You plan a trip. You break it down into air travels, hotels, etc. for
each city and search the best deals for each of one them.

Better Solution

Instead you build a complete itinerary of your trip including when you
would like to visit a city, places you would visit in the city, a radius
within which you would like to stay (or this could be calculated
optimally from other data), hotel preferences, duration of the stay,
etc. The site then finds the best deal for the complete trip.