Olivet University - Olivet Institute of Technology

Teach Yourself Programming in Ten Years

Why is everyone in such a rush?

Walk into any bookstore, and you’ll see how to Teach Yourself Java in 7 Days alongside endless variations offering to teach Visual Basic, Windows, the Internet, and so on in a few days or hours. I did the following power search at Amazon.com:

     pubdate: after 1992 and title: days and
      (title: learn or title: teach yourself)

and got back 248 hits. The first 78 were computer books (number 79 was Learn Bengali in 30 days). I replaced “days” with “hours” and got remarkably similar results: 253 more books, with 77 computer books followed by Teach Yourself Grammar and Style in 24 Hours at number 78. Out of the top 200 total, 96% were computer books.

The conclusion is that either people are in a big rush to learn about computers, or that computers are somehow fabulously easier to learn than anything else. There are no books on how to learn Beethoven, or Quantum Physics, or even Dog Grooming in a few days. Felleisen et al. give a nod to this trend in their book How to Design Programs, when they say “Bad programming is easy. Idiots can learn it in 21 days, even if they are dummies.

All-in-all, a very interesting post by Peter Norvig, read the full article here.

Software Engineering Distilled

This is my attempt at distilling software engineering into 20 tweets (<140 characters). Not entirely sure that it is wholly satisfactory. Please try your own!

Plan your process. Share it and keep it under constant revision. Use a well understood process template. Drive process improvement. #softeng

Identify your stakeholders. Ensure continuing engagement. Collectively own major tradeoffs. Get management buy-in. #softeng 

Work out boundaries of your problem & framing assumptions about behaviour of the real-world. Establish extent of your confidence in these. #softeng 

The biggest determinant of success will be the skills & experience of the team. Choose well. #softeng 

Build requirements collaboratively with stakeholders alongside a schedule of incremental delivery. Jointly plan test & evaluation. #softeng 

Confront risks early. Changes get much more expensive as development proceeds. Organise to minimise these costs. #softeng 

System evolution is inevitable. The system will change the application setting. This will require system change in turn. #softeng 

Build a long-term development roadmap. Measure progress against it. Keep it constantly updated. #softeng 

System requirements: security, reliability et al determine architecture. Changes have big impacts. Think about usability at outset. #softeng 

Eschew novelty. Use established patterns. Build for understandability. Distrust clever solutions. Reuse whenever possible. #softeng 

Keep solution architecture as close as possible to problem structure. focus on getting the component interfaces right. #softeng 

Use modelling to ensure you have a good shared understanding of problem structure. If you can embed model in a language do this. #softeng 

Keep tight fine-grain version control of all your artefacts. Organise, link, tag & add metadata. You never know when you need it. #softeng 

Take nothing on trust, most of all your own instincts about what is correct. #softeng
Invest in your tools. Invest in your skills. #softeng 

Regression tests. Enough said. #softeng 

Pin down uncertainty using focussed prototypes. Exploit maths, domain specific languages, functional programming & formal methods. #softeng 

Do not let your client persuade you into unrealistic schedule commitments. Leave time & budget to reengineer & refactor. #softeng 

Effective management demands a deep knowledge of and commitment to engineering. Avoid know-nothing project managers. #softeng 

Organise for learning. Measure & assess. Debate quality. Reflect on successes & failures. Do better next time. #softeng

Source: Software Engineering Distilled

Google PageRank checksum PHP algorithm revealed

In a blog entry, the Google PageRank checksum algorithm was revealed.

The Google PageRank functionality in Google Toolbar works by querying Google’s server for information on the PageRank of a specific page. This might seem easy enough to implement in your own program/website, but the problem is that the toolbar calculates a checksum on the page URL before querying the server, and the server only responds if the checksum is correct. Fortunately the checksum algorithm was reverse engineered from Google Toolbar 7. I was provided the hand decompiled version of the algorithm in C from a friend. Then I went ahead and rewrote it in PHP for web development usage. You can find both versions below.

As an example, the query URL for the page ‘http://en.wikipedia.org/wiki/Cypherpunk’ is http://toolbarqueries.google.com/tbr?client=navclient-auto&features=Rank&q=info:http://en.wikipedia.org/wiki/Cypherpunk&ch=783735859783

Any other query with a checksum other than 783735859783 will result in a ‘403 forbidden’ response.
Enjoy.

PHP CODE:

<?php

/* the floating point hacks are due

   to PHP's bugs when handling

   large unsigned integers */

functionfch($csm)

{

    if($csm< 0)

        $csm+= 4294967296.0;

    $a= (int)fmod($csm, 10);

    $t= 1;

    $b= (int)($csm/ 10);

    while($b) {

        $c= $b% 10;

        if($t)

            $c= (int)($c/ 5) + ($c* 2) % 10;

        $b= (int)($b/ 10);

        $a+= $c;

        $t^= 1;

    }

    

    $a= 10 - $a% 10;

    if($a== 10)

        returnord('0');

    

    if($t)

        returnord('0') + (int)(($a& 1 ? $a+ 9 : $a) / 2);

    returnord('0') + $a;

}

functionchecksum($str)

{

    if(strlen($str) == 0)

        return0x1000;

        

    /* the floating point hacks are due to PHP's bugs when handling integers */

    $a= 5381.0;

    for($i= 0; $i< strlen($str); $i++)

        $a= fmod($a+ ($a* 32) + ord($str[$i]), 4294967296.0);

    if($a> 2147483647.0)

        $a-= 4294967296.0;

    $a= (int)$a;

    $b= 0.0;

    for($i= 0; $i< strlen($str); $i++)

        $b= fmod(($b* 64) + ($b* 65536) - $b+ ord($str[$i]), 4294967296.0);

    if($b> 2147483647.0)

        $b-= 4294967296.0;

    $b= (int)$b;

    

    $a= (($a>> 6) & 0x3ffffc0) | (($a>> 2) & 0x3f);

    $c= (($a>> 4) & 0x3ffc00) | ($a& 0x3ff);

    $d= (($c>> 4) & 0x3c000) | ($c& 0x3fff);

    $c= ((($d& 0x3c0) << 4) | ($d& 0x3c)) << 2;

    $a= $b& 0x0f0f;

    $e= $b& 0x0f0f0000;

    $b= (($d& 0xffffc000) << 4) | ($d& 0x3c00);

    return($b<< 10) | $c| $a| $e;

}

$PR_SERVER= "http://toolbarqueries.google.com/tbr?client=navclient-auto&features=Rank&q=info:";

$page= "http://en.wikipedia.org/wiki/Cypherpunk";

$csm= checksum($page);

printf($PR_SERVER. "%s&ch=7%c%u\n", $page, fch($csm), $csm);

?>

Productivity vs. Guilt and Self-Loathing

The guilt can be crushing. Everyone seems to be getting stuff done, except you. You drag yourself out of bed, go to work, start checking email, start deleting, then poof, it’s noon. Lunch, perhaps at your desk, then some awful meetings, then it’s 3pm. You start REALLY working, then you start feeling decent but then it’s 5pm or 6pm. It’s time to start getting home. You feel like you didn’t really get a lot done today so you’ll work late - just tonight - to catch up.

Here’s what I do when I’m feeling non-productive and guilty. Again, watch the video for more details, it’s not selling anything and I go into more detail. I need to just write a small book on this..

• Stop Checking Email in the Morning
• Don’t make Guilt Piles 
• If it’s important, Schedule It. 
• Measure, then Cut 
• Do smaller things 
• Let go of Psychic Weight 
• Schedule Work Sprints 
• Stop Beating Yourself Up

Read full post here : Productivity vs. Guilt and Self-Loathing

Why can’t the IT industry deliver large, faultless projects quickly as in other industries?

A interesting and insightful discussion emerged as to why the it industry can’t deliver large faultless projects quickly as in other industries that deal with other huge projects, such as Airbus or skyscrapers.

Read full discussion here : http://programmers.stackexchange.com/questions/158640/why-cant-the-it-industry-deliver-large-faultless-projects-quickly-as-in-other