Markandey's Blog

How to fix *.OGV file to upload on YouTube (for Ubuntu 10.04 LTS users)

2010-09-07T15:08:00.000-07:00

Hi Guys,
Just sharing my experience with *.ogv, while I was trying to upload a video on YouTube.
I was using Ubuntu 10.04 LTS and used gtk-recordMyDesktop to record a screencast and uploaded the video on YouTube, I found that youtube is showing completely gabbled video.

I could not figure out the problem but i simply converted the video to avi and uploaded on youtube, problem solved!!

How to convert to avi?
Basically you have 3 options.

Using mencoder.
Using ffmpeg.
Using DeVeDE.

The only option which worked really nice with me is mencoder (use following command)

mencoder input.ogv -ovc xvid -oac mp3lame -xvidencopts pass=1 -o output.avi

Problem with other 2 options ( i observed)

DeVeDe was converting correctly, but messing up with the length of video.
ffmpeg completely failed to convert (was gabbling the video like Youtube).

To install mencoder use ubuntu software center.

Portable wire-free Wi-Fi Router in India

2010-09-06T23:51:00.000-07:00

Tata has launched a new product “TATA Photon Wi-Fi Router”. With this, you can now create a portable hotspot anytime, anywhere. It is a device that enables you to share Wi-Fi with up to 5 users/devices simultaneously to access internet: Imagine the whole family accessing the internet from their respective devices – iPod Touch, WiFi enabled smartphone, laptop – on the go, all using this one portable router!

Introductory price is 4999/-

Device is powered by rechargeable Li-ion Battery.
More Information find here

How to use Javascript beautifier with gedit.

2010-07-17T02:44:00.000-07:00

Javascript beautifier is an awesome online tool to indent your JavaScript code. I use it very often.
Earlier I use to paste my code in this online tool to get my JavaScript code indented.
Fortunately there is a way to integrate javascript beautifier with gedit.
Here are steps(I hope u are using latest version Ubuntu Linux, and having python).
Step1:Install gedit plugin "External Tools".
open gedit and go to edit->preferences->plugins(tab)
see if you already have a plugin "External Tools", if not install using this command.

$ sudo apt-get install gedit-plugins

After inslalling enable this plugin from edit->preferences->plugins(tab).
Step2: Install Rhino Shell.
You need Rhino Shell, to execute javascript on commandline.
To check whether you already have "Rhino Shell" or not, type "js" on Command Line.
You can Install "Rhino Shell" by typing this command.

$ sudo apt-get install rhino

Step3: Download einars-js-beautify.
You can download it here http://github.com/einars/js-beautify .
Extract it in some folder. lets say you have extracted it in folder
"/home/markandey/dev/einars-js-beautify/" .

Step4: Configure plugin to use jsbeautify.
Now go to "gedit->tools->manage external tools" and add a new command script, with following description.

Description: Beautify Javascript using einars jsbeautify
Shortcut Key:
Commands:

#!/usr/bin/env python

import os
import sys
import tempfile

jsbeautify_path = "/home/markandey/dev/einars-js-beautify/"

content = sys.stdin.read()
h, tmpfile = tempfile.mkstemp()
os.close(h)

f = open(tmpfile, "w")
f.write(content)
f.close()

cmd = "js beautify-cl.js -i 4 %s"%(tmpfile)
os.chdir(jsbeautify_path)
content = os.system(cmd)
os.remove(tmpfile)

use these attributes.
Input: Current Selection.
Output: Replace the current selection.
Applicability: All documents.

That's it! you are done!

Thanks for reading my blog.

Chrome Extension to do YQL page scraping. (quickest way to create a YQL mashup)

2010-07-26T13:46:00.000-07:00

Hello ,
This weekend I was in Bangalore to attend "Yahoo Hack Day", Where I wrote a hack, which is a Chrome Extension to make your life really easy when you are trying to do some page scraping using YQL. My hack is also the "winning hack".

Name of the extension is ChromYQLip, which you can install from here.

Here is demo video

Yahoo hack days are great event, this time in India total participants were more that 450 and a total of 142 Hacks submitted and 108 hacks presented.

Thanks for reading My blog

What a software engineer can learn from YSR’s death

2009-09-05T10:14:00.001-07:00

[Background: YSR was Chief Minister of Andhra Pradesh (state) of India. He died in a chopper crash.]

One of the reason media figured out for YSR death is “he ignored safety processes/guidelines, and he influenced the aviation staff to fly during bad weather condition”.
Now question is whose mistake??
Is it the mistake of CM to influence staff who takes care of safety guidelines? Or it’s the mistake of staff that he got influenced???
I believe it’s the mistake of staff.
Very often this happens in software industry as well, we are given some tight schedule and we are forced to finish it. How you act in such scenario?? Mostly we try to finish that within deadline and we skip essential steps e.g. we skip unit testing, we skip code reviews and all of above we tend to write quick and dirty code.
Before doing anything like that you should ask a question to you.
Which is more dangerous?
· Refusing to work on tight guideline?
· Or writing quick and dirty code, and skipping process guideline?
Act accordingly!!
I personally refuse to work on tight guideline many time, because I think that might annoy my Boss for a moment but when something will go seriously wrong after product delivery, it might annoy whole company.
[sad about the death of a mass leader]

HindiTransliteration (c# and JavaScript implementation, works offline)

2010-06-13T21:51:00.000-07:00

When I was in college, I wrote a quick and dirty code to transliterate in Hindi (DevNagari Script). Much before Google's Implementation.
{This code was kept on my old desktop PC,I Thought, its a good idea to share with the rest of the world}

Though my implementation is not very robust, but Its very simple and small. It does not require any Internet connection and can work offline.

Note: code was originally written in C#.net and converted to javascript latter.
Here is C#.net Code(solution zipped)

You need to call function

DoTransLitrate(str)

Where str(as input): Phonetically typed (in English) Hindi .
Returns: Hindi in Devnagari script.

Using JavaScript Code
Get the JavaScript File from here include in your html page and call function

DoTransLitrate()

  DEMO

Kill All Chrome Instance at once (Linux+ Windows)

2010-06-07T23:04:00.000-07:00

Windows users can follow this instructions here.
Or simply use command

taskkill /F /IM chrome.exe

Linux geeks can use this command

kill -9 `ps -A |grep chrome| cut -d "?" -f1`

How This works?
I am sure that, most of the Linux users can easily figure it out, but for those who want explanation here you go...
Command
  ps -A    list all the processes
  grep chorme    will filter only those process which has name as chrome
  cut -d "?" will cut the process Id potion of the out put.
and
  kill -9 kills a process ,
so above command will kill all the process with name chrome.
Please Note that this command will work on those processes which are not command line (mostly launched from UI ) (i.e whose tty field is "?")

How to write your own spell checker ? C#.net

2010-03-26T06:08:00.000-07:00

Hi There,
Today I wrote a readable & usable implementation of Norvig's Spell corrector.
Norvi's implementation of spell check is awesome! On his site he has link to many other implementation in various languages, including C#.

Most of the implementation are focused on minimum number of lines , so they are not readable. I have written my own implementation which you can use on your own risk.

Here is the source code

You can also check-out entire code using this svn command

svn checkout https://jugad.googlecode.com/svn/trunk/C%23/SpellCheck SpellCheck

How Algorithm works?

1.Initially Algorithms builds a dictionary* data-structure of words, from a huge English text. (so algorithm does not uses dictionary# file as such). This dictionary* contains words-to-frequency-of-occurrence mapping. lets say it as nWords.

2.When you will fetch a word(lets say 'w') for spell correction,Then the algorithm builds a list of all possible words that can be formed from w by doing following operation

Deletion (delete 1 character, for all possible combination)
Transposition (flip 1 character, for all possible combination)
Alteration (modify 1 character, for all possible combination)
Insertion (insert 1 character, for all possible combination)

Lets say name of this list is 'edits' , note that all words in this list are just 1 step away from original word.
3. If edits has 1 or more words that exists in nWords, then it returns the word from nWords with maximum frequency, as a result.
4. If No words in 'edits' are present in nWords, then it creates another edits using edits to get second level word (word which are 2 step away from original input word)
5.Repeats from step-3 (or give up if your are already 2/3 steps apart from original word 'w')
Read more Here.

How To Use This code ?
To use this code instantiate class spell by passing huge-string of English text (from where it will build dictionary)
Then call function correct() to get the corrected word as result.

Note:This code is just to demonstrate the algorithm, modify constructor to build dictionary directly from file. You can also avoid calling sort operation in function 'correct'. Thoroughly understand the code before using it. Notify me if you find any critical problem.

*dictionary data-structure of programming
#real dictionary

Twenital: Determines gender from a twitter handle

2010-05-19T01:51:00.000-07:00

Twitter never stores the gender of their users. It makes the life of analytic engines very difficult to find that what is the ratio of men vs women on twitter.
Here I have created quick and dirty mash-up to get gender of the twitter user.

How It Works?
Thanks to face.com API, they have recently released face recognition API. I am simply using their face recognition API to do this.

Here is AJAX code

function getusergender(imageurl) {
var url = 'http://api.face.com/faces/detect.json?api_key=1ce92a4c5e60f04c37bedf86c2d19387&urls=' + imageurl + '&callback=?';
$.getJSON(url, function (data) {
if (data.status == "success") {
if (data.photos[0].tags.length == 0) {
$("#resdiv").html('<div class="errormsg">hmmm..Let him/her put better profile picture. </b>TIP: put high resolution profile picture, facing front.</div>');
}
else if (data.photos[0].tags.length > 1) {
showerror('This user is multifaceted, Let him/her put better profile picture..');
}
else {
if (data.photos[0].tags[0].attributes.gender.value) {
var gender = data.photos[0].tags[0].attributes.gender.value;
if (data.photos[0].tags[0].attributes.gender.confidence > 40) {
if (gender == 'male') {
$("#resdiv").text('100% Male');
}
else {
$("#resdiv").text('Gorgeous Female');
}

}
else {
if (gender == 'male') {
$("#resdiv").text('Male');
}
else {
$("#resdiv").text('Female');
}
}
}
else {
showerror('hmmm... not sure!!');
}

}
}
else {
if (data.usage.used > 197) {
showerror('Sorry!! Application Overloaded!!');
}
else {
showerror('Processing failed!! Can not determine gender!!');
}
}
});

}

DEMO

Offline Google Maps in C#.net

2010-05-19T01:19:00.000-07:00

Sometime back I wrote an application for windows mobile in c#.net which can give you turn-by-turn navigation on phone completely offline. Map and direction info will be pulled by a peer Desktop application which will export all these information in an XML file. This XML file will have these 2 Items

Static Map Images (covering the track at zoomed & top level))
Direction steps and description.

Static map images can be downloaded from Google using there static map API. Direction steps and descriptions can only be downloaded via a AJAX API. Since I had only AJAX way of getting this data, I created a webpage which can do all necessary DOM operation using JavaScript. Once the DOM is populated I can easily grab the data from C# API (Web browser control + GetElementByID APIs).

Downloading the static Images from Google is not enough, you need to map Latitude and Longitude on the static map. Which is done like this

public PixelPoint GetCordinateOnStaticImage(double latitude, double longitude, 
double centerLat, 
double centerLang, 
int zoom,
double width,
double height)
{

       long val = 1 << ((21 - zoom));
       double target_y = LatToY(latitude); 
       double target_x = LongToX(longitude);
       double delta_x = (((target_x - LongToX(centerLang))) / (val));
       double delta_y  =(((target_y - LatToY(centerLat)) )/ (val));
       double marker_x = (width/2) + delta_x;
       double marker_y = (height/2) + delta_y;
       PixelPoint p = new PixelPoint(marker_x,marker_y);
       return p;
}

You can see Full source code here. Originally Idea is taken from here.

Direction
Google returns the poly-line of the direction path. Some of the points on this polyline will be identified as step, step has direction description, e.g "at blah blah circle take left".
This project solve another problem of pulling the right direction description from the given location.

SourceCode
Complete source-code of this project is available on Google code here.

Demo
Here is a demo video.

How to organize life using twitter?

2010-03-21T04:41:00.000-07:00

{Happy Birthday To Twitter, Today on 21st March 2010, little bird (twitter) is all grown up. }

Today in this article I am going to tell you some little tip to organize your life with twitter. Read my old article about how I have linked my social network.

Twitter is popular because of 2 main reasons, Simplicity & Accessibility. Twitter Updates (tweets) are just 140 character long, and you can post these update from any media e.g Browser, twitter clients, phone client, by SMS or even by writing down on paper.

For centuries there are 2 very popular ways of organizing life,
1.Note Making
2.ToDo List
Despite these things being a popular way of organizing life, majority of people fails to maintain a single note-book or a ToDo list, because if your life is so organized to maintain a ToDo List or notebook then probably you never need them. Point is, either you are using a paper, phone, iPod or your laptop to maintain your ToDo list , none of them is accessible all the time & everywhere. Eventually this accessibility problem is almost solved by twitter, So there can not be any better tool like twitter to organize your life.

I always loved 2 tools on web for maintaining my todo list and notes, because they are also accessible via twitter.

EverNote
EverNote is very nice note making tool. I am not going to tell you much about it. You can just go an try it. I love its web-clip boorkmarklet to take note while browsing. Addition to specific client it has for iPhone, Android and Win-Mobile, You can also add a note in EverNote by just @replying to @myen or send a DM(direct message) to it. Now since tweet can be posted by all ways described above , you can access your note from every where.

e.g
note to self "kill all currupt politicians" @myen
OR
d myen think about explaination why photo frame is better than diamond necklace on valentine's day

Remember The Milk

Remember the milk has a very similar accessibility options as EverNote, the difference is in aproach, This is a ToDo list for task management. You can also access it by sending DM to @rtm

e.g.
d rtm pick up the milk
d rtm !complete call jimmy

Search Your Tweets
Here is last tip, Since twitter has become your primary place to dump thoughts, Its better to have a way to search your tweets. Twitter search is a real time search, it only gives you results from a very small time-frame, sometime you might like to search your old tweets. To get this functionality here is a hack, subscribe your twitter feed in Google Reader, Google readers stores all the feeds subscribed by you and indexes it, so that you can search them latter. RSS feed of your tweets will be at this address (if you have unprotected updates only)

http://twitter.com/statuses/user_timeline/[your TWITTER HANDLE].rss

Thanks for reading my blog. Hope this was helpful. Please share on twitter and Facebook if you liked it.

Understanding C#.net Border-less Form, when you maximize it

2010-01-28T02:57:00.000-08:00

Hi There,
Have you ever created, a borderless window in C#.net?
There is problem with borderless window, if you maximize it, it goes FullScreen (over the taskbar).

Here is an analyis of how to achieve maximized borderless window.

If you first set the border(anything other than FormBorderStyle.None) for the window and then set WindowState to maximize, You will get a standard maximized window, you can make it border-less there after.





private void btMaximize_Click(object sender, EventArgs e)
{
 this.FormBorderStyle = FormBorderStyle.FixedSingle;

 if (this.WindowState != FormWindowState.Maximized)
 {
  this.WindowState = FormWindowState.Maximized;
 }
 else
 {
  this.WindowState = FormWindowState.Normal;
  
 }

 this.FormBorderStyle = FormBorderStyle.None;
}

If you maximize a window after making it borderless it goes beyond the task-bar. You will get complete full-screen.




private void btFullscreen_Click(object sender, EventArgs e)
{
 this.FormBorderStyle = FormBorderStyle.None;
        if (this.WindowState != FormWindowState.Maximized)
 {
  
  this.WindowState = FormWindowState.Maximized;
 }
 else
 {
  this.WindowState = FormWindowState.Normal;
 }
 
}

Download Sample Code

How to add Tabs on blogger?

2009-06-25T03:24:00.000-07:00

[This is old post, you can follow easy steps , with new blogger template designer here]
Here is a step by step procedure to add tabs for your blogger.

STEP-1 Go to Blogger Dash board

STEP-2 Go to layout section of your blog, and go to edit HTML
[Save your template, to make sure that if anything will go wrong, you can restore the things back]
STEP-3: Grab this code

#tabsB {
      float:left;
      width:100%;
      background:#F4F4F4;
      font-size:93%;
      line-height:normal;
      }
    #tabsB ul {
 margin:0;
 padding:10px 10px 0 50px;
 list-style:none;
      }
    #tabsB li {
      display:inline;
      margin:0;
      padding:0;
      }
    #tabsB a {
      float:left;
      background:url("http://sites.google.com/site/hackbit/tableftB.gif") no-repeat left top;
      margin:0;
      padding:0 0 0 4px;
      text-decoration:none;
      }
    #tabsB a span {
      float:left;
      display:block;
      background:url("http://sites.google.com/site/hackbit/tabrightB.gif") no-repeat right top;
      padding:5px 15px 4px 6px;
      color:#666;
      }
    /* Commented Backslash Hack hides rule from IE5-Mac \*/
    #tabsB a span {float:none;}
    /* End IE5-Mac hack */
    #tabsB a:hover span {
      color:#000;
      }
    #tabsB a:hover {
      background-position:0% -42px;
      }
    #tabsB a:hover span {
      background-position:100% -42px;
      }

STEP-4 Paste this code(above code) just after body CSS which will look like this

body { 
background:$bgcolor; margin:0; 
color:$textcolor; 
font:x-small Georgia Serif; 
font-size/* */:/**/small; font-size: /**/small; 
text-align: center; 
}

STEP-5 Grab following code (customize the link as per your need)

<div id="tabsB"> 
  <ul> 
    <li><a href="#" title="Link 1"><span>Link 1</span></a></li> 
    <li><a href="#" title="Link 2"><span>Link 2</span></a></li> 
    <li><a href="#" title="Link 3"><span>Link 3</span></a></li> 
    <li><a href="#" title="Longer Link Text"><span>Longer Link Text</span></a></li> 
    <li><a href="#" title="Link 5"><span>Link 5</span></a></li> 
    <li><a href="#" title="Link 6"><span>Link 6</span></a></li> 
 <li><a href="#" title="Link 7"><span>Link 7</span></a></li> 
  </ul> 
</div>

STEP-6 Paste the above code in you HTML template after header section (the line which will look like this)

<b:widget id="Header1" locked="true" title="Experimenting Blogger (Header)" type="Header">
</b:widget>

STEP-6 Done!!, save the template and view your blog
You can get some different kind of tab design here

Working Demo

Create quick and dirty YQL Mash-up in 10 seconds (using MashupBuilder)

2010-04-19T11:37:00.000-07:00

Sometime, you might have experienced that you have to wait till whole website is downloaded just to see a stock-quote, game score, or league points table(etc.). Mostly these kind of websites are poorly managed, and they are very slow or contains too many annoying ads. I have created a Mash-up-builder that will help you in creating YQL based mash-up, very quickly. These mash-ups will be capable of showing just a small portion of the original web page. Mash-up will be dynamic and content will be pulled from original page every-time you will visit the mash-up. Additionally mash-up will be hosted on my website, so you need not to bother about hosting, though you can copy HTML code anytime if you want to host on your own.(these mashups are pure JavaScript, no server side coding).

Advantage is getting a faster & neat web page.

It was very easy to create mash-up-builder. I used YQL's html table.

How it works?
As you see that YQL's HTML table gives you output if you provide the URL and xpath of the content. Similarly Mash-up builder take 2 parameters as input, a URL of the web page and an XPATH of the content. Once these 2 things are ready, I cleverly used JSONP to render the content on page.

I recommend you to see the source {view-source} to understand the working of the mash-up.

Warning
Since mash-up builder injects HTML content directly from external source, its prone to CrossSite Scripting attack. My website is not hosting any private content , so to me its fine because no security can be breached, do not try to replicate this functionality on your website if your website is hosting some private content.

LIVE DEMO

Feel free to share on twitter, Facebook & other social networking sites.

IPL Tables made sortable

2010-04-03T17:40:00.000-07:00

Ever since I visited the official IPL website, I hated those static points table.

So I used YQL to grab that data and place in very sortable fashion here.

To create this I am using,
YQL
Google visualization API (optionally one can use YUI)
Jquery tabs

Top 11 Language Concepts That Every Developer Should Know

2009-08-09T15:32:00.001-07:00

There are a few fundamental things we have invented in programming languages,
which was invented at various point of time, particularly by one language and they were later adapted by many other languages.
I am going to list some of them, which have bigger impacts.

DataType
The first and foremost thing which we have ever invented is the data type. Computers were just a dumb machine, which could only understand the binary sequence. Binary sequence made no sense till it was grouped to form a DataType.
As you know a DataType, is something which groups the binary sequence together and represents some entity in mathematical word OR real word. All depends on its interpretation.
DataType is not just a grouping of binary sequence but also a set of operations which it posses. I mean a DataType definition just don't end with its binary grouping but also the operation which can be performed on those entities.
Later we have evolved these DataTypes into more complex form. We used mathematics to bring various complex data structures like List, Stack, Queue etc.
Today almost every programming language directly or indirectly have concept of data type.

Pointers
With the invention of computers, we've also invented the concept of loading and storing data from Hardware. Computers accesses memory by toggling special bit patterns in the wires (which was called data bus). This led to the invention of Pointers in our high level programming languages.
Pointers specially became popular in C programming language. Pointer is one of the most popular programming concepts ever invented. Other than C language, pointers are supported by languages like C++,C#, Fortran, Pascal. Few dialects of BASIC also supports pointer.

Structured Programming
Most of the programs in the early days were completely relying on GOTO statements, which was a real mess and was making programmers life real hell. Now that's where we have invented the "structured programming " another fundamental programming concept. Through this concept we have brought something called functions, and subsequently we realized the power of abstraction.

OOPs
I think OOPs (Object Oriented Programming) is one of the most popular and ever lasting fundamental concept we have invented in history of programming languages. OOps is an umbrella concept. We have brought many concepts under this.Concepts like Data hiding, Inheritance, abstraction, polymorphisms (static & dynamic) were just the beginning of OOps. OOps is available directly or indirectly in almost all modern languages. Languages like C++, java & c# have brought it a long way.

Regular Expression
Regular expressions provide a concise and flexible means for identifying patterns in string. This is used for searching and replacing special pattern in a string.If your favourite programming language is supporting Regular Expressions, and you are still thinking of learning,then this is the time to go and learn. Regular Expressions are now supported by many languages (almost all popular programming languages). Additionally Regular expression became standard language for many find and replace system utilities. Unix command (utility) Grep is one of the most popularly known Regular Expression based utility. Regular Expressions became so popular concept that many programming languages made it as the part of there language syntax (construct).Languages like Perl, Ruby and TCL embraced regular expression as their primary language construct.

SQL
With the invention of Relational database, where everything is stored in the form of Tables, SQL type of languages evolved. This was mainly developed for data query, data update, schema creation & schema modification. They became so popular that it was extended to make procedural SQL.
With the popularity of SQL, recently Google has brought GQL to abstract their Big Table ( a non relational data base). SQL like syntax is also borrowed by yahoo in YQL, to query data from anywhere on internet. LINQ in C#.net, is also inspired from SQL.

Managed Heap
Managed Heap OR Smart pointers, was another revolutionary concept which was invented as a hack of OOps concept (classes ) in C++. This was invented by Microsoft in a concept called COM. Smart Pointer, solved the problem of memory leak .
This concept was later adapted as default language semantic in programming languages like Java & C#. Later this was adapted by many programming languages like VB.net and Managed C++.

XPATH
XPath is another programming concept which was developed to access DOM tree, and became a preferred way to access the XML formatted data. This is another programming paradigm which you should be aware of, If by any chance you work with XML.

Duck Typing
The Term “Duck Typing” is invented by Python, though the concept of duck typing is old and was there in few languages earlier than Python.In duck typing, programmer is concerned with just those aspects of an object that are used, rather than with the type of the object itself.
Let's understand this. Let us say we have a real life object Shape, which knows how to draw itself (with a method draw). Now in OOps, We enforce this by creating an interface something like IDraw, any anything which can be drawn on the screen must be of type IDraw(i.e It should be inheriting IDraw). I Duck Typing, object can be drawn on the screen as long as object holds the draw method,irrespective of the type of object. DuckTyping removed the dependency of common interface definition, which are typically shared by client and server modules in OOps languages. Disadvantage of such thing is, programmer will not be able to know at the compile time, that the object is not having the draw method in it. But wait, python does not have compile time, its interpreted language, so all the problem can only be identified during the runtime.
One thing i am sure about DuckTyping is that it is very risky deal when you are building a big (cathedral like) software. But it is very good when you are writing very small quick and dirty lines of code.
Duck Typing is supported by Python, JavaScript(and similar languages) & C# (for your surprise, read this nice example).
Duck Typing helps a lot in JavaScript, in fact the concept of “JSON based AJAX” is completely based of duck typing.
Duck typing is a very controversial concept, many OOPs lovers hate this concept.

Closure
Some languages (e.g. JavaScript) allows you to define a function inside another function. Closure is the scope, which inner function is having. Coolest part of closure is, scope remains valid even after outer function have returned.
One of the nice example of closure is this (in JavaScript), Inner function dofading will still be having access to ‘Div_InClosureScope’ even after the Fade have returned.

function Fade(id)
{
var Div_InClosureScope= document.getElementById(id);
var level=0;
function dofading()
{
var hex=level.toString(16);
Div_InClosureScope.style.backgroundColor='#ff'+hex+hex+hex+hex;
if(level<15)
{
level++;
setTimeout(dofading,100);
}
}
setTimeout(dofading,10);
}

In more general term, closure is a special scope, provided to a special instance of a function. In OPPs the member function enjoys closure (data members are in closure scope). Programming language C does not have closure concept at all. Its a most simple and straight language.

Yield
I found this technique first in python.This was not something new, but can confuse most the programmers from c/c++ background. This technique somehow stores state of iterator (I will explain latter), and returns different result at different time, and this is something c/c++ programmers are not used to. Any C/C++ programmer assumes a function is a stateless machine, which can return only one result for given set of argument, no matter how many time you going call that function.

A Python function stack can be unwrapped( retuned) in 2 ways, by a return statement or by a yield statement. A return statement stops the execution of a function (same as in c/c++ ). On the other hand an yield statement halts the execution of a function and store the state, so that when it will be invoked later, execution will start from the same point.

Lets take an example of typical Fibonacci number generator.

#An endless generator
def fibonacci():
i = j = 1
while True:
r, i, j = i, j, i + j #respective assignment
yield r

for rabbits in fibonacci():
print rabbits,
if rabbits > 100: break

Output
1 1 2 3 5 8 13 21 34 55 89 144

Python certainly support, C++ like return statement, but using yield is most efficient for this such generators. All those recursive way of writing Fibonacci number generators are really inefficient( though they look simple).
Yield statement is also supported by C#.net. Here is one of the nice post about yield in c#. Do not miss!

I love this article, "Life after loops". somehow, its connected to this blog post

Fartastic [Fart application for pocketpc (windows mobile) ]

2009-03-03T11:38:00.000-08:00

(original file from http://www.dailyhaha.com/_pics/fart_date.jpg)

Hi guys,
Here is a fart application for Pocket PC .
So download the application from here

DOWNLOAD

and enjoy farting on your pocket pc...

what is fart application?
For the people who are ignorant about fart application here is a brief. This is an application which does nothing but produces farting sound after every 10 seconds or so. The fart sound is randomly chosen from the list of few sampled sound.
The only use of such application is to do some naughty stuff. Its up to you to find naughty things. like u can enjoy people making weird faces, when you start this application in elevator (lifts) and put in your pocket.

Sorry for large size of installation, have to put the wav file inside...!! (around 5MB) :(

PocketPC Fart iFart Windows Mobile win mobile ppc pocket pc fart app

Fix JSON based Ajax in Chrome

2009-05-07T12:23:00.001-07:00

I love JSON, because its very easy to work with JSON than working with XML. If you don't know what JSON is please read in detail here http://www.json.org/.
Here i am discussing the use of JSON and the JSON retrieval method for AJAX. This method does not work in Chrome, because chrome maintains a JavaScript cache. I will discuss the fix of this problem as well.
Lets take an example code, which will grab data from twitter search and it will display on your page.

<html>
<head>
<script>


   1:  
   2:     function getsearch()
   3:     {
   4:       var search_url='http://search.twitter.com/search.json?callback=mycallback&q=';
   5:       /*search_url will fetch you JSON with callback name as mycallback*/
   6:       var query='';
   7:       query=document.getElementById('query').value;
   8:       search_url=search_url+query;
   9:       var scrpt_div = document.getElementById('script_div');
  10:       scrpt_div.innerHTML = '';
  11:       var scrpt_ele = document.createElement('script');
  12:       scrpt_ele.src = search_url;
  13:       scrpt_div.appendChild(scrpt_ele);
  14:       var result_div = document.getElementById('result_div');
  15:       result_div.innerHTML = 'loading....';
  16:     }
  17:     function mycallback(data)
  18:     {
  19:       /*write code here to do the JOB*/
  20:       var html='';
  21:       for(var i=0;i<data.results.length;i++) 
  22:       { 
  23:         var tweet=data.results[i].text/*aah.. luxury of jus using the data, no parsing*/
  24:         html=html+tweet+'<br/>';
  25:         
  26:       }
  27:       var result_div = document.getElementById('result_div');
  28:       result_div.innerHTML = html;
  29:     }
  30:   
</script></head><body><div><form  action="javascript:void(0)"> <input id="query" type="text"></input> <input type="submit" onclick="getsearch();" value="search"></input> </form> </div><div id="result_div"><!--Here your Result will appear         --></div><div id="script_div"><!--Here your JSON script will come             <script src="http://search.twitter.com/search.json?callback=mycallback&q=hello">      </script>    --></div></body></html>

Get this code in plain here .

In this code above, we are simply embedding a script element in the DOM whose src attribute will be the URL to retrieve JSON data (e.g http://search.twitter.com/search.json?q=hello’.) The URL will contain the call-back so that retrieving the JavaScript code for this element will result in calling your call back function and hence you will be able to use this JSON data in your call-back function.

The above code is hosted here, so try Demo1

If you try this code in Chrome browser, for a same query it will not work for the second time! Reason is Chrome does smart caching of JavaScript. So if it will find that the new script tag has same src URL, it will not include that for second time, and hence it will not work second time in chrome.To fix this problem, I have added in extra parameter in the JSON query URL. which will be a fake counter.
Instead of JSON URL like this

var search_url='http://search.twitter.com/search.json?callback=mycallback&q=';

you can modify by adding extra query parameter which does not mean anything to server. like this :

var search_url='http://search.twitter.com/search.json?callback=mycallback&count='+fake_counter+'&q=';

Increase the fake_counter on every call. So that new URL will be different from the previous one. This will fix the problem in chrome.

Now this fix code in PlainText is here and Demo2 is here

How to add custom about me page on blogger

2010-03-17T04:12:00.000-07:00

Hi There,
Here I am going to talk about a dirty hack to make custom about me page on blogger. Lets have a look what you are going to get after doing all this.

So, Basically you are going to make an blog post which will contain "about me information" which you wanted to put on your blog. Then you will remove date entry(time stamp) / and comment option for this page so that it will not look like a post.
Note: Save your existing template before, doing anything. If you break anything , you can restore the template back.
STEP-1
Create a blog post with title "about me" and content whatever you want. Then go to Post option

STEP-2

Go to post option and click "Don't allow comment" and Set time-stamp to a very old date (may be much before your birth).

Step-3
To remove time-stamp from this post your have to wrap part of code which generates Time stamp in your template with this code.

<b:if cond='data:post.allowComments'>



</b:if>

This is basically a way to tell that whatever "post does not allow comment" will not generate few things (which is time-stamp in our case).
Step-4
Go to layout section of your blog, and go to edit HTML. Choose "Expand Widget Templates" option.

Now select all the text from Text area and put in your favorite "Text Editor" . (FYI My favorite editor is Notepad++).

Now wrap following 2 block with code above

<h2 class='date-header'><span><data:post.dateHeader/></span></h2>

AND

<div class='post-footer-line post-footer-line-1'>

Part-1

Part-2

Once you are done with this editing, go paste the entire thing back to blogger text-area and save the template.

Note: You should wrap the code very carefully, basic HTML knowledge is very essential for this. Every Div block starts and ends some where , so wrapping must be perfect.

You can link the URL of the page on "About Me Tab" Read My other post.

Thats it, Your are done!!!

How to get Tabs (navigation bar) on new blogger templates

2010-03-25T11:41:00.000-07:00

Hi There,
First of all you might have seen that blogger has brought-up new Template Designer. This article is to tell you that "how can you add tabs in these new templates?"

Its very easy

Open http://draft.blogger.com/home
Go To layout section and add a page element of type "HTML/Javascript" just below "Blog Header"
Now add this code in the widget.

<ul>
<li><a href="http://sampleurl.com">Sample URL</a></li>
<li><a href="http://example.com" >Example Links</a></li>
</ul>

Note that between ul tag you can add many as li items as you want.
each li item will have a anchor ("a") element whose href property needs to be set to the URL you want this tab to link, and text portion goes in between.

customize this code as you want, and then paste them in the widget section.
save your widget and enjoy the tabs.

Thanks for reading my blog

Awesome QUESTIONS are back

2010-03-20T19:54:00.000-07:00

Do not miss the part-1 and part-2 of awesome questions. AND here are few more

If love of money is the root of all evil, why do churches want it?
If love is blind, why is lingerie so popular?
If Jimmy cracks corn & no one cares, why is there a stupid song about him?
If it’s true that we are here to help others, then what exactly are the others here for?
If it takes more muscles to frown than smile, then wouldn’t unhappy people’s faces be in better shape?
If I save time, when do I get it back ?
If I save the whales, where do I keep them?
If flying is so safe, why do they call the airport the terminal?
If electricity comes from electrons, does that mean that morality comes from morons?
If you are reading a very INTERESTING book about anti-gravity. Can you put it down?
How can an email be both URGENT & FYI?
If vegetarians eat vegetables, what do humanitarians eat?
Why do people make loud nosies when there tryin to make someone be quiet?
If past tense of sit is sat, why not past tense of fit is fat?
People say "The moment u stop learning u r dead", then why population is still increasing?

Thanks Guys have fun :)

If you have any awesome question about the blog, please post as comment. Do share on twitter and Facebook if you like it.

Few more awesome questions..

2009-06-29T12:48:00.001-07:00

Thanks for all your appreciation for my last post, Here is some more question, which are more funnier that previous list.

If white house is white, the blue house is blue, and the red house is red. Why green house is transparent?
Why all of the black boxes are painted bright orange?
If there is a substance exist, which can make Black Box indestructible, why not same thing is used to make whole aircraft?
Why black paint smells like a green paint?
Why there is flotation devices under plane seats instead of parachutes?
What's another word for thesaurus?
Why is it that when you transport something by car, it's called a shipment, but when you transport something by ship, it's called cargo?
Why I get a phone call from Vodafone to say my bill was outstanding? (I always say thanks)
I understand money talks, but why it always say "goodbye" to me?
How can a burnt match thrown from a car start a forest fire when 2 boxes of matches, 10 fire lighters & lighter fuel can't light a BBQ?
What will happen if a abortion clinic will have a 12 months waiting time?
Why isn't the number 11 pronounced onety one?
Ever wonder what the speed of lightning would be if it didn't zigzag?
If people from Poland are called Poles, why aren't people from Holland called Holes?

Chrome Extension to analyse tweeter (Twitter User) Behavior

2010-03-16T12:07:00.000-07:00

Recently I was looking on various sites that shows some statistics about tweeters (twitter user). They are great but they often focus on one thing, there is no single place where we can see all these analysis. So i closely analysed these websites to come-up with YQL hack to bring all of them on a single page. Mainly I focused myself on these websites.

http://twitterholic.com/
http://web.forret.com/tools/twitter-tq.asp
http://tweeps.info/
http://happytweets.com/
http://tweeteffect.com/

TweetChrome

[I am also trying to pull information from http://tweetstats.com]

Well if I would have hosted this functionality something like this (actually hosted ). No one will use it, because people are very lazy. So I have created a chrome extension here.

If you use chrome then you can simple see source code here.

Thanks for reading my blog.

Demo: http://chrome.google.com/extensions/detail/pmdeehablhbendnpdligdgemdgkllmih

Source: http://www.purplegene.com/static/tweeps.html (do view source)

YQL hack to get DZone popular articles on 1 page

2009-08-27T11:46:00.001-07:00

Problem with DZone feed is, it contains the link to DZone page. No way i can jump to article, skipping the DZone page. At the end of this article You will be getting a simple YQL based hack to get a DZone popular links on 1 page linked to original blog page.
Note: if you are not interested in how i got it Jump to Demo.
STEP-1
Using YQL first get the popular links. using feed table (use YQL console).
URL to popular link feed is http://feeds.dzone.com/dzone/frontpage
So my YQL query will be.
select * from feed where url='http://feeds.dzone.com/dzone/frontpage'

You will get the details of all popular articles linked to Dzone’s page (same as in feed).
I am just interested in links so my YQL will be (replace * by link).
select link from feed where url='http://feeds.dzone.com/dzone/frontpage'
STEP-2
With all those link retrieved in the step-1, get the HTML page out of it. get the title node using an XPath query .
First by simple DOM inspection i can figure out that title node is wrapped in a DIV element whose class name is ‘ldTitle’.
select * from html where url in (select link from feed where url='http://feeds.dzone.com/dzone/frontpage') and xpath='//div[@class="ldTitle"]/a'
Select format as XML and grab the REST URL
which will look like this

http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%20in%20(select%20link%20from%20feed%20where%20url%3D'http%3A%2F%2Ffeeds.dzone.com%2Fdzone%2Ffrontpage')%20and%0A%20%20%20%20%20%20xpath%3D'%2F%2Fdiv%5B%40class%3D%22ldTitle%22%5D%2Fa'&format=xml

STEP-3
Now Time to do some tweaking. if i get this data in XML i have to parse it. if i will get it in JSON, JavaScript will do all the parsing for me. That's why i love JSON.
Now if i get everything in JSON i have to regenerate DOM via a JavaScript code. I am lazy to do even that. So i want result formatted in JSON and DOM section as it is(i.e. in XML).
I can do this by putting a call-back as argument in above REST URL.
so my REST URL will be

My call back name is ‘loadlist’. so lets implement this call-back.
which is like this.

function loadlist(data)
{
var content_div=document.getElementById('content');
if(!data.query)
{

content_div.innerHTML="error.. failed to load"
}
else
{
var i=0;
var html="";
for(i=0;i<data.query.count;i++)
{
html= html+data.results[i]+"<br/>";
}
content_div.innerHTML=html;
}
}

To see the full source code, visit this page and view source code. I have implemented extra function ‘track’ for some purpose. .

DEMO

Hacking Google maps AJAX API to use in C#.Net

2010-01-17T10:10:00.000-08:00

Hi,
As you know “Google Maps API” is available only for AJAX developers. Using it in C#.net is not possible. One of the great things about Google maps API is it gives you turn by turn direction almost anywhere on earth. I wanted to exploit this feature of turn by turn navigation on my mobile, that too offline, because when i go to remote places its highly probable that i will not be having connectivity on my phone. Or connectivity will be so poor that using maps is highly impractical.

So I have created a pair of application.
1. A Desktop app to retrieve turn by turn navigation data + static images.
2. A Mobile app to read this data and to give me turn by turn navigation on phone (offline).

Certainly this is something not allowed in TOU of Google, so i cannot release this app commercially.

How to Mix AJAX and C#.net??
1. I created a web page (html+JavaScript), which dumps the direction info data in DOM.
2.In C#.Net Form, I kept a web-browser control, which loads this page.
3.When page is loaded, using webBrowser1.Document.GetElementById stuff I extracted the direction info.
4.Then I downloaded Static Images using "Google Static Maps API", & hacked to get the latitude and longitude positions on the static images. see code for detail.

How I exported data on mobile??
1. Serialized whole object in an XML file, including direction info and static images.
2. De-serialized on mobile to get that data back.

Source Code
http://code.google.com/p/pocketnavigator/

Screen-shot Of Mobile Version.

Demo of Desktop App (6 minute).

Thanks, Feel free to ask question, & share on twitter + digg & blah blah.