dragozov.com

Moving on

2011-11-15T01:55:00.003Z

I'll be leaving Popcap in the end of December. I'm halfway through my 3 months (!!!) notice and it's now just a question of winding up my work and spending the last few weeks with my colleagues.

It's the fourth place in a row where I decide that I've had enough and it's time to move on (in fact, the only time when I didn't leave by choice is when they kicked me out for mixing alcohol and water at a bar where I worked as a student, but that's a different story).
Maybe it's just me, but jobs feel like a snake's skin - sooner or later you reach the limit and the only way to grow is to throw it and get a new one.

This time it's different though. Instead of looking for work at someone else's company, I'll focus on my own ideas and try to create products and a business around them. I won't be calling it a startup yet and don't want to hype it too much. It's just a few things I'd like to try and I'll spend the next 6-12 months looking for gold nuggets or getting my butt kicked by the universe.

Thankfully the last 12 years gave me the experience to believe I know what I'm doing and enough savings to be able to afford an experiment or two. But probably the most important, I can count on my family for all the support and all the pressure I can wish for (and maybe a little more).
Plus I've already done some crazy things that looked pretty impossible in the beginning. It can't be that much harder than loosing 40 kilograms or running a marathon.
Right?

R.I.P. Steve Jobs

2011-10-06T19:47:00.002+01:00

A really sad day.

Diversity

2011-09-16T23:58:00.002+01:00

Why on earth are people so different?!
What I see as the end, is the beginning for someone.
And often my dreams are the nightmares for others.

Thank god that people are so different!
Or no one would take over when I've had enough.
And my dreams would be all worn-out and crowded.

What's next?

2011-09-07T22:17:00.001+01:00

I haven't blogged much lately, mostly because I was busy, but also because some pretty exciting things were happening at my current job and I was waiting for things to settle.
Now it's all done and dusted. And my life is completely upside-down!

I've never imagined that being so free to choose what to do next would be that frightening.
Should I pick some of the less risky options or do I just jump and do what I've always dreamed of? What if I choose wrong? What if I fail? Am I capable enough? Can I afford it?
It's so much easier when there is someone or something to blame, when there are "good" reasons to delay your decisions and your plans for the future are in the future.

So what will I do?
Haven't quite decided yet. Though one thing is for sure - there will be changes. Soon!

Until then I'll be doing lots of traveling, meeting people, talking to family and friends and figuring out things.
Oh, and I'll be writing here much more frequently .

uplift.in

2011-06-22T21:57:00.003+01:00

I'm somewhat of a domain addict. If I encounter a nice unregistered or expiring domain and can think of a cool idea to match it, I'd register the name as a reminder. Then every time I have to do some maintenance at my registrar, I'd go through the list of currently unused domains (it's just a few, I'm not a squatter) and for each idea revisit if I want to do something about it immediately, hold on it for a little longer or just forget it and drop the name.

Uplift.in is one such domain that I bought last year with the idea of building a service for publishing only positive, feel-good, uplifting news. For one or another reason I feel like starting this now and pushed an initial version last night.
It's a stock installation of Pligg at the moment, but I'll be working on the design and the content in the next few months. There may be also some additional cool features on the "roadmap".
By the way I have no business plan about this and there won't be ads on the site. Just a nice community service to warm you up:)

IQ Pushups

2011-06-15T19:34:00.004+01:00

I've been playing with Brain Workshop lately. It's a free (open source) software that implements the dual task n-back exercise and lets you play with different levels of difficulty.

What is n-back?
According to some recent research this is brain-training that actually works. Do it 20 minutes per day for a few weeks and chances are you'll be measurably smarter (for a very specific definition of smart)!
Like with physical exercise mileage could vary, but it's still pretty fascinating news.

So nothing surprising in the sudden spike of intelligence at this blog.

An ice age ahead?

2011-06-14T21:06:00.006+01:00

I find this piece of science news quite ironic. It's like the Universe is showing us its middle finger to remind us how small and insignificant we are.

Surprising results from 3 projects researching the Sun point to a big drop in the solar activity for the next few decades. This may (or may not) trigger a global ice age for most of the century or at least could slow down the mess of a global warming we are causing to the planet.
Not that it's going to solve much of our problems anyway. We'll still need lots of clean air, fresh water and food and who knows how much of the Earth's already struggling flora and fauna can survive a potential freeze. Plus we'll have to burn lots of coal and oil to keep those 7 billion and growing bodies warm.
On the bright side the polar bears may be safe (for a while).

Monitoring the execution of asynchronous JavaScript callbacks

2011-06-14T00:21:00.002+01:00

In JavaScript sometimes it's useful to know if an asynchronous callback function was called, how many times and if it completed or failed. Of course you could implement it by changing some state in the outside scope, but this means adding code to the function and it won't work for existing 3rd party code.
I've written a small jQuery extension, jquery.monitor.js, (there is no actual jQuery dependency in the implementation by the way) which creates a wrapper around the callback function that keeps the latest call status and history in a property called monitor.

Example:


var m = $.monitor(mycall);//wrap the callback, m.monitor.status is 'unused'
$.getJSON("my.json", m()); //calling m() prepares a callback and sets m.monitor.status to 'queued'
$.getJSON("another.json", m());

When the callback starts, m.monitor.status will be set to 'called' and when it completes it will become 'completed' or 'failed' if it raised an exception.

In addition there are 4 counters for the history of each state: monitor.queued, monitor.called, monitor.completed and monitor.failed (in the example above m.monitor.queued and m.monitor.called will be 2 and the sum of m.monitor.completed and m.monitor.failed will be equal to 2).
To check if all queued calls have completed use the m.isPending method (for this to work the result from calling m() should not be reused for consecutive callbacks!!!) and to reset the monitor use the m.clearMonitor method.

2011 marathons

2011-06-12T12:47:00.003+01:00

My plan is to run 4 full marathons in 2011. I already did Connemara in April and have finally decided on the other 3:
1. The Galway City Marathon on 28th August
2. The Dublin Marathon on 31st October
3. The Clonakilty Waterfront Marathon on 10th December

The big goal is to run in less than 3:30h by the end of the year. It shouldn't be too hard, but I I'll need to get lighter and faster, which means loosing some weight (at least 10kg, but maybe even more) and doing some serious running (minimum 60km per week) in the next 6 months .

jquery.defaults.js

2011-06-09T23:44:00.016+01:00

JavaScript doesn't let you define default values for arguments of functions, which, considering their heavy use throughout the language, can be quite a pain.
In addition, a very common pattern is to use one of the arguments of the function as a collection of name:value options and to add an object with their default values inside the function's scope. However repeating the same code every time is not that nice and adding it to external functions requires even more work.

My new jQuery extension jquery.defaults.js to the rescue!
It adds two functions to jQuery, defaults and options. They both return a wrapper around their first argument, with defaults setting default values for the arguments' list and options implementing the pattern described above.

Examples:

var f1 = $.defaults(f, [1, undefined, "3"]);//using an array of default values


var f1 = $.defaults(f, {"0":1, 2: "3"});//the same using an object with the argument positions as keys

Calling f1() will pass (1, undefined, "3") while calling f1("a", 2) will pass ("a", 2, "3").

var f2 = $.options(f, {key:"value", a:"a"});//the position of the options argument is 0 by default
var f3 = $.options(f, 2, {key1: "value1"});//but it can be explicitly declared as the 2nd argument

Calling f2({a:"b"}) will pass ({a:"b", key:"value"}), while calling f3(1) will pass (1, undefined, {key1: "value1"}).

The functions resulting from applying the two can be mixed and chained together as much as necessary for even cooler effects.

Grab the code from my GitHub project bits.and.pieces.js and check the unit tests in the test folder for more examples. There is also a minified version if you feel like using it in production.

RoadID

2011-06-08T18:31:00.008+01:00

My RoadID arrived with the mail this morning and it's had its first 10 km run already.

What is it?
It is one of those very simple, but clever ideas that make perfect sense once you've heard about them. A friend called it jokingly "a dog-tag" and it kinda does the same job.
RoadID is a small metal tag with engraved important contacts and information, medical or anything else, that you wear on your wrist or ankle. I got the ankle version as it also doubles as a place for your timing chip when running in a competition.

Why you need it?
I run 40-60 km every week (mostly country roads and forests when I'm home, or unfamilliar streets and parks when I'm travelling). With this little metal plate I have the peace of mind that all my details and my family will be immediately available in case of an emergency. And it's a pretty cool dog-tag too ;)

The Last Lecture

2011-06-08T00:11:00.005+01:00

What better topic for my first "daily note" than "The Last Lecture" of Prof. Randy Pausch? I happened to watch it for 3rd or 4th time this Saturday and it's still one of the most inspiring talks you could find online.

It's not so much about what he says. Most of it has been said before.
But the fact that he is a dying man with nothing to gain, makes it all sound so real and honest that it hurts.

And it's totally amazing how you finish watching a little sad, but also smiling and full of energy and love for life. And even if you cried (I guess most people do) you've also laughed a lot. A cocktail of feelings that will stick in your brain for days.

Daily Notes

2011-06-07T23:53:00.005+01:00

As a small experiment in self-discipline I will try to write a blog post every day.
Starting now...

Connemarathon

2011-04-08T16:30:00.003+01:00

I'm running in the 2011 Connemara marathon this Sunday (10th April).
It's supposed to be the most scenic but also the hardest in Ireland. And I'm also running in Vibram FiveFingers so should be fun :)

Running

2010-10-18T18:58:00.001+01:00

I'll be running in the Dublin marathon next Monday, 25th October.
It's my first marathon, I've been training since April and my main goal is to finish.

However I'm also raising funds for UNICEF, hoping to help their efforts to improve health, education and safety for the children of the world.
You can support my run by donating here (or at the UNICEF website if you are reading this after the event):

Donate Now!

UPDATE: I finished in 3:42 hours and it didn't feel hard at all. Now I'm totally hooked and will be doing it a few times per year.

Treaps in Erlang

2010-08-01T22:09:00.007+01:00

After a few months break I'm back to working on a project written mainly in Erlang and I'll be posting the most interesting pieces online to a small open-source project at Google Code, ErlAZ - Erlang A to Z.
The first module I'm uploading is an implementation of the Treap data structure.

What is a Treap?
It's a binary search tree where each node, in addition to its key and value, contains a number, called priority, assigned to it at insertion time.
All nodes are sorted horizontally by their key (so that a greater key is always to the right of a smaller one) and vertically by their priority (so that all parents of any given node up to the root have a higher priority than the node).
By choosing the priorities uniformly distributed across all keys (for example randomly), in the long run the treap will have the characteristic of a well-balanced tree, without having to re-balance it periodically.

I implemented my version as a drop-in replacement for the dict module, with all the dict functions having exactly the same signiture and behaviour, but working on treaps and performing according to the underlying tree structure vs. the hashtable used in dict.
There are also a few additional functions that use the ordered nature of the tree to allow querying and iterating over the keys in a sorted manner (which is pretty much the point of using a treap anyway), as well as functions for splitting the treap in two by a key (the first sub-treap contains all nodes with keys less or equal to the given key and the second - all nodes with greater keys) and for merging back a splitted treap.

The treap module comes with well documented functions and an extensive EUnit test suit (in a separate module treap_test), which contains tests and examples for the usage of each function.
As always all the code I release is covered by the New BSD License unless stated otherwise.
This means you are free to use it in any way you like, so help yourself:

ErlAZ trunk - The ErlAZ project's root with the Makefile for building the code and its documentation.

treap.erl - The treap module.

treap_test.erl - The treap_test module with all the EUnit tests.

Earth Day Sunshine

2010-04-05T17:39:00.004+01:00

Just in time for the Earth Day 2010 I got a solar water-heating system fitted in our house. I'll be writing more about what it does, how it works, post pictures and first impression in a week or two, but in the spirit of the day I'm writing a few sentences about my reasons.

Do I believe it makes any difference? Would it save the world? Stop global warming? Of course not.

Do I think that teaching my kids and their friends about sustainability and giving a personal example is important?
That showing my neighbors how solar technology is not a curiosity anymore, but an affordable alternative, is the best way to get their attention?
Do I feel good about supporting a business that's investing and creating jobs in a green-tech industry?
You bet!

So Happy Earth Day and maybe focus less on the today's problems and more on the future solutions.

Happy First App To Me

2010-02-17T01:41:00.016Z

My first iPhone project StencilsApp was approved by Apple today and just appeared in the AppStore here in Ireland.
Contrary to the widespread rumors, the approval process was a breeze, the review team was extremely professional and it all took less than 14 days.
Considering the fact that StencilsApp is a complex and rather unique tool, rich in content and text (you see what I'm doing here), my respect for what Apple have built in the last 3 years just grew even more.
I'll definitely be sticking with their platform and the AppStore for the foreseeable future.

What is StencilsApp?
It's a native prototyping (or wire-framing, mock-up etc) tool for the iPhone and the iPod Touch. Probably the first of its kind.
It lets you design user interfaces and software using the native components of the device and produces sketches as close to the real app as you can get without programing it.
The results simulate the complete work-flow of an iPhone application through UI transitions and annotations triggered by the user's taps or gestures on the screen.

It's easy to use and you don't even have to know anything about programming. My 9 year old daughter is sketching with it quite successfully.
I'm hoping it would be useful both for non-programmers to visualize and communicate their ideas and for iPhone developers to prototype, test and receive approval for their projects.

It has lots of cool features, like 2D drawing, a large free icon library, a set of templates, app samples, online sharing etc.
Just check the video tutorials that I've put on the web site.
And if you own an iPhone or an iPod Touch, why not just grab it from the AppStore, while it's hot ;)
It's a free download (with some optional stuff purchasable from inside the app if you feel like supporting my work):
iTunes Link

I'll be writing more about my experience and the technology behind StencilsApp in the next few weeks and I'll probably open-source some of the code when I get time to clean it up.
But at the moment all I care for is to get my first decent sleep in the last 7 months.
Yes, that's how long it took, but hey I'm a married guy with two kids and a busy, full-time job.
Plus, as I said, it's quite a complex and powerful tool ;-)

Diving into Erlang with Project Euler, Part 1

2009-12-27T15:18:00.000Z

Project who?

Project Euler is probably the largest (270 problems as of December 2009) and best collection of brainteasers specifically designed for programmers. Unlike other puzzles they are not only fun and challenging, but also help you discover and develop new patterns and programming techniques. I'm a big fan of similar computational mind-benders and use them both in job interviews to see how a candidate approaches a real problem and as a way to balance the boring work that's frequently necessary for even the most interesting projects.
I've been solving 1-2 problems every day and after completing number 25 today I got a nice message:

"Bravo, dragozov! Now that you have solved 25 problems you have achieved what 80.04% of members have failed to do and have advanced to level 1. Good luck as you continue."

So I thought I'd describe my experience, especially considering that I'm using Erlang, a language that I'm currently trying to master and which could use a little more sample code and demos online.

Why Erlang?

I'm working on a small side project and one of the decisions I made was to focus on learning new things and exploring technologies and problems that I find interesting, but are not useful or relevant to my day job. So I'm developing everything as a combination of Erlang and Python.
Of course I have more pragmatic reasons. Erlang's unique features make lots of sense for some parts of my app and the two languages complement each other quite well. I also wanted to experiment a little more with functional programming and I find the mental shift required to code in Erlang quite enjoyable. I guess the recent hype around the language played its role too.
Anyway I've been studying Erlang and OTP (the open source platform behind it) and use any chance to apply my new skills, so Project Euler was too good of an opportunity to miss.

The Idea

In this and the follow-up articles I'm showing how to use Erlang to solve computational problems. As I advance from the simpler questions to the harder ones, I'll try to also move from the language's basics to more advanced topics.
However this is not an introduction and I won't be explaining the syntax. There are a few good online tutorials and an excellent book, so you might want to check them first.
On the other hand I'll point out Erlang specific features and techniques and discuss their usage. I also keep the solutions as self-contained as possible, so in some cases there might be code implementing functionality that is already available in the standard libraries or functions copied between the modules.
I've tried to find the best solutions I could think of and optimize the code as much as possible, but I haven't searched the Internet or checked the forums, so there might be better/faster algorithms. There is rarely a single correct way of doing things in programming and this is not an exception.
I'll keep all solution sources in a Google Code project called Eulerl. The license is BSD, if you care, so you are free to use them for anything you like.