timsort visualization

This blog post is quite effective at illustrating the timsort algorithm, found in python (and soon java)

vim zen moment

There comes a certain time in one's life to put aside the variety of editors they might use or sometimes dabble in, and perhaps choose one they like best, or see the most potential with down the road, and work monogamously toward advanced proficiency in this editor, regardless of the bumps in the road or hardships which may provoke longing for other editors along the way.

I've made this commitment to vim recently and I'm still a novice.
But I just had what may be my first true zen moment with the editor!

The problem:
* I needed to fix a single spacing annoyance in a set of over 40 php files.

The solution:
* Open all php files rooted in foo, luckily 90% were all at the same leaf level
vim /foo/*/*/*\.php
* Start recording a macro in register a
qa
* Make edits
[a fair bit of jj and dd and i etc.]
* Write changes
:w
* Open next file
:bn
* Stop recording
q

After pressing @a a few times to execute the macro, or :bn if the file could be left alone, I was done.

I've always wanted to be able to do this sort of thing so easily, but it's elusive or cumbersome with most GUI editors. Many UNIX text munging tools exist too, but it's often easier to take direct route of showing the machine what you want, rather than, say, building a DFA.

So, I'm liking the taste of vim kool-aid thus far.

Smack talkin' D.R. Hofstadter delivers sick iceburn on R. Kurzweil

This is a profound interview with Douglas Hofstadter, author of Goedel Escher Bach and I Am a Strange Loop.

Money Quote/Excerpt:

I think Ray Kurzweil is terrified by his own mortality and deeply longs to avoid death. I understand this obsession of his and am even somehow touched by its ferocious intensity, but I think it badly distorts his vision. As I see it, Kurzweil's desperate hopes seriously cloud his scientific objectivity.

...Kurzweil sees technology as progressing so deterministically fast (Moore's Law, etc.) that inevitably, within a few decades, hardware will be so fast and nanotechnology so advanced that things unbelievable to us now will be easily doable. A key element in this whole vision is that no one will need to understand the mind or brain in order to copy a particular human's mind with perfect accuracy, because trillions of tiny “nanobots” will swarm through the bloodstream in the human brain and will report back all the “wiring details” of that particular brain, which at that point constitute a very complex table of data that can be fed into a universal computer program that executes neuron-firings, and presto — that individual's mind has been reinstantiated in an electronic medium...

Rather ironically, this vision totally bypasses the need for cognitive science or AI, because all one needs is the detailed wiring plan of a brain and then it's a piece of cake to copy the brain in other media. And thus, says Kurzweil, we will have achieved immortal souls that live on (and potentially forever) in superfast computational hardware — and Kurzweil sees this happening so soon that he is banking on his own brain being thus “uploaded” into superfast hardware and hence he expects (or at least he loudly proclaims that he expects) to become literally immortal — and not in the way Chopin is quasi-immortal, with just little shards of his soul remaining, but with his whole soul preserved forever.

Well, the problem is that a soul by itself would go crazy; it has to live in a vastly complex world, and it has to cohabit that world with many other souls, commingling with them just as we do here on earth. To be sure, Kurzweil sees those things as no problem, either — we'll have virtual worlds galore, “up there” in Cyberheaven, and of course there will be souls by the barrelful all running on the same hardware. And Kurzweil sees the new software souls as intermingling in all sorts of unanticipated and unimaginable ways.

Well, to me, this “glorious” new world would be the end of humanity as we know it.

Hopefully you're hooked by now, so read the rest!

Loblaw's law

When you have numbers that are really really really big, you can stop talking about probabilities and start talking about laws.

Statistics are often unintuitive for people, and the Monty Hall Problem is a famous example of that un-intuition in action.

And of course, as humans, we distrust machines. And statistics are, so far, the best tool machines have for imitating humans in areas such as language and vision. How we hate these machines, with their statistics.

Yes, so if you are a human reading this, you may feel a certain amount of smugness knowing that language is a built-in feature for you; you can read an article and comprehend with absolute certainty its key points and discuss it in an intelligent and natural way. Even if a computer were able to analyze the same article, it could only offer up soulless suggestions of meaning with varying degrees of certainty, and with little or no actual intelligence.

But as it turns out, you and I live in a crazy universe not governed by laws so much as statistics.

Mandatory Djikstra quote: The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.

On their own, atoms can be in several possible states, each with varying probabilities, where the most probable state has lowest energy.

With more heat added to a closed system such as a gas, the likelihood that each atom is in a higher energy state increases. Each macro state view of the entire system is equally likely, keeping in mind that particles are coaxed from lower micro energy levels with likelihood directly linked to the work performed on the system. All arrangements of molecules in the container are equally likely and they are all interchangeable with one another.

Now if you were to take each of these equally likely macro energy states and group them in buckets by total energy level of the system, the distribution would produce a bell curve. So, looking at this bell curve, you could state with some amount of certainty the likely range of energy (temperature actually).

EXCEPT, that's not how the universe actually works!!

The contradiction arises because the number of particles is on the order of 10^23.

So there's still a bell curve, but it's not really a curve so much as an extremely tall spike with almost zero width and almost no variance. Temperature and entropy and the first and second "laws" of thermodynamics all work because 10^23 is an enormous, enormous number, and the expected value (the center of the curve) is the only value anyone actually ever experiences.

To illustrate I'll create a law right now, named after a brilliant attorney, called Loblaw's law. Loblaw's law states that it is not possible to flip a (normal) coin 10^23 times and produce only heads each time. You may say, well technically that is still possible, so how can it be a law?

Well, technically it is (sort of) also possible for the entropy of the universe to decrease for a few minutes. Technically, it is also possible that heat could flow from a cold object to a hot object. Technically, a broken egg could assemble itself from the floor and leap back into my hand...blah blah blah, Loblaw's law is a law because these events are so unlikely that it they will never happen.

That's the way it goes with ginormous numbers, and that's why we can call them the laws of thermodyamics, although a better name for the field is actually Statistical Mechanics.

Back to computers, the point is that statistics is a strength, not a weakness of computers which may perform natural language processing, image recognition, or other tasks wherein humans naturally have the upper hand. Feed a somewhat sophisticated AI a few petabytes of salient data and I believe suddenly that Dijkstra quote will ring true.

Dtrace

Up until very recently I had never heard of Dtrace.

Sun Microsystems, makers of brilliant software but not money, created Dtrace for their Solaris OS. It allows you to create probes and listen on a port where syscalls or other OS events are reported.

This is awesome and also ported over to Mac OS X. This set of one-liners gives a small example of what's possible. If you're on a mac or FreeBSD or Solaris (!) and looking for a good time try running a few of these.

And if you have Instruments installed, you can launch apps and monitor their calls, file I/O, memory leakage, etc...

For my own personal Rube Goldberg machine, I might write a Dtrace script which listens for whenever files of a certain type are opened, and pipe them to a script which automatically backs them up using some version control.

Or similarly, automating other tasks such as running make whenever code files are written.

I was excited to learn about and had never heard of Dtrace, so I thought I'd share, enjoy!

11 week Project Manager Manifesto

If you are taking a project course that lasts 11 weeks, and you are leading a group of 5-8 software engineers, congratulations, you are a project manager for CSE 403!

Read this post-mortem fresh from the source, the project manager on Robot Rock. Robot Rock is an open-source interactive music framework built in 11 weeks by 5 UW undergrads for CSE 403, a software engineering course.

Suggested reading:
The Pragmatic Programmer
How To Win Friends and Influence People

At the beginning

You are the one to set the tone. Work as hard as it takes to get the project off the ground, and demonstrate what your expectations are. The sooner you demonstrate that the project could be a success, the sooner you win the rest of the team's dedicated efforts, and you can't get far without that.

This is the time for experimentation--it will never get easier to test out different concepts!

For example, Robot Rock started with separate demos of drum sounds in a loop and a trivial non-functional UI. Mashing these together was a major milestone and morale boost, demonstrating the fact that all of our technologies can live and work together in the same environment in a doubtful time when we still struggled to set it all up.

It also provided a tangible way to demonstrate that a lot of the hard work was already done, and was useful for settling disputes through experimentation instead of abstract arguments (for example, when designing architecture based on the performance limitations of our libraries).

Establish regular meeting times during the week, and hold onto this inertia. Meeting often is the best thing your group can do.

Don't think of yourself as any sort of authority, think of yourself as the sniffable glue keeping your team happy and productive and it's up to you to figure out exactly how to make that happen! If you read Dune you know that as soon as you start giving orders, people stop acting autonomously, so don’t command, lead instead.

Testing

Write lots of tests in the beginning, but keep them fairly general/flexible since things will be fairly tumultuous at the start and tests will die quick and noisy deaths.

You need the tests for just two purposes: to verify and enlighten. Tests help maintain confidence and momentum, and allow you to breath easy knowing that you aren't breaking anything as you hurtle with breakneck speed through the rapid development which takes place after the design is settled. Of course, with all this code, you need a way to demonstrate what it all does. Tests are a great way to communicate to your team mates how to actually use the code you're writing.

Don't let tests prevent refactoring--accept that you will have to some tedious effort fixing them up. If you hate the thought of this, don't go hog wild writing tests for things likely to change, and write professional tests which don't have lots of repeated code.

Don't leave your tests broken.

Planning

Assembla is a hugely valuable tool. It integrates a ticket system, file hosting, milestone tracking, wiki, and repository with online code browsing.

Use the wiki to maintain your documentation and deliverables. Use the milestone tracking to organize and shuffle your tickets around in time.

As soon as you think of something that needs to be done, create a ticket for it.

Design

So, you're in 403, which means you're writing code for 11 weeks, then throwing it away, right? There's some truth to this, but if you write ugly code you can't use it to convince people to hire you. Often job postings require an example of code you've written to solve a non-trivial problem, and so this is your chance to shine to all future employers.

There are a lot of general things which constitute a good design, such as modularity, simplicity, modules which are decoupled, interfaces, etc.

This isn't really about bad design/good design though. You want a design which will make your high level goals natural to achieve.

For example, we knew at the start that it was critical for Robot Rock's music to feel very responsive and sensitive to user manipulations.

We also knew that we wanted the audio generation to have no influence over the rest of the design, in case we wanted to drastically change the way we generate the actual musical tones.

From these first principles, we could evaluate each potential design (everyone came up with a rough design as a homework assignment) and examine if it allowed for real time responsiveness, as well as decoupled abstract song data from the underlying generation. Once these requirements were met, we went on to examine other more general qualitative characteristics, such as separation of components and simplicity.

If we started with an arbitrary design goal, such as simplicity, we may have locked ourselves into a design where real time responsiveness was anything but natural, despite whatever other elegance is achieved. In other words, we would have picked A Good Design, but it'd be The Wrong Design.

Features

Build the simplest thing that meets the requirements.

If there's a feature you want to add, consult your users first. Make a prototype before investing the time in something which the user may not actually care about.

No optimization until feature complete, or later even.

Understand when code is good enough...I'm just parroting The Pragmatic Programmer at this point, so just read that instead.

Grow Experts

Assign each group member an area of ownership. It doesn't have to be something they are familiar with, just something they care the most about ideally. There should be no part of the project without an associated leader. Everyone can just refer to this person for questions, and it will deepen their understanding of the respective area. It also provides resume bullet points.

Not everyone will have the same knowledge level of the languages you use. It helps to have at least one person experienced with each language utilized, and they should oversee code reviews with the less experienced members, at least during the initial stages. It goes without saying that the instruction and learning are the crucial goals for these code reviews, never judgment.

Teamwork

I forget where I read this, but the difference between a team and a group is that a group all leaves a meeting at its deadline regardless of where things stand, whereas a team will stay as long as it takes to get things to a satisfactory point.

In practice this makes no sense. Sometimes people really do have to be somewhere at a certain time, and sometimes despite your best efforts, you have to force a less than ideal resolution. But the idea is not to leave things open and unresolved at the end of the day. Make some sort of plan for the next session, or if someone can stay and play cleanup, they should and earn the gratitude of the group. Make sure it's not the same person every week.

Get the entire group involved. If someone's quiet, explicitly invite them to weigh in with their position. Assign homework to the whole group to prepare a decision on items which affect the overall team course. Send around status updates during times when everyone's too busy on different areas to meet.

Code and documentation is communal. If any problem is found, it's your problem to fix, regardless of its origin. No drawing territorial boundary lines, if it's someone else's code, take it as an opportunity to learn about its inner workings.

When Conflict Occurs

Let everyone speak their minds, and focus on the ideas, not the person.

Try to be the first to find and acknowledge the weaknesses of your own idea, and the strengths of each opposing idea.

Find common ground. Find and point out things about ideas you disagree that are positive, and be sincere.

If the discussion drags on, put it to a group vote. Once the group decides, that's it, no revisiting the topic until taking action to make things work as they stand.

Think Big

Able developers seek worthy, difficult projects to grow their skills. Give yourselves a difficult and interesting project, so you'll attract hungry developers, and everyone will rise to meet the challenge.

How to buy coffee

If you're a consumer in the market for 'specialty' coffee (i.e. anything above Folger's grade) then there are a myriad of options, brands, and considerations designed to address concerns ranging from taste, to environmental impact, and social justice.

Fair Trade is the most well-known label, designed to protect the price points of workers on small coffee farms. Although it guarantees a floor price for the coffee and other protections for the workers, even experts who support Fair Trade, such as Mark Pendergrast, are quick to point out its limitations.

Fair Trade can only offer protections to a small percentage of the workers in the coffee trade since large and medium farms aren't eligible, and quality is left to its purchasers to determine.

Certified organic coffee may seem likely to benefit the health of coffee consumers, but its real impact lies elsewhere. In a speaking engagment at the University of Washington, Pendergrast noted that the pesticides affect the cherry hulls, and don't penetrate to the bean itself. Drinking organic coffee, then, does not necessarily offer a health benefit over traditional methods, but it does benefit the workers who harvest the cherries by hand, and are exposed to the poisons.

Beyond fair trade and organic, there is direct trade, which has no certification, and several bird friendly/shade grown certifications which have numerous variants.

With careful research, you may learn about the organizations and certifications involved for these different brands and labels, or discover a roaster which participates in Direct Trade practices which are agreeable with your purchasing habits.

Yet, for whichever stories come printed on the label or distributed in information on certification practices, however, they simply remain stories. The truth about the chain from the farm to the cup often remains unknowable opaque, and is spun by marketing professionals looking to cash in on the conscientious consumer of specialty roasts.

For a glimpse of what could be the reality of direct trade coffee, for example, look no further than this review of Zoka coffee roasters (my emphasis):

I worked for Zoka for a little over a year and in that time I saw: sexual harassment (from the head of the company which made the girl move out of town), failure to pay coffee farmers, threats from various upper management to the employees (I can't tell you how many times I heard the head of the company say "You have to like me, I'm your boss!", firing people for calling in sick and finally their finniest and latest: embezzlement of employees tips to make up for the money that was lost during a break in. The owner does not care about anything but himself and his money which he has no idea how to manage.

Although I'd like to believe that purchasing specialty coffee with certifications from international organizations is making the world a better place, clearly there is still a certain amount faith involved and the actual results are difficult to know.

My recommendation to the truly conscientious consumer: buy organic Hawaiian coffee. It may be expensive, but:

• You are buying American products, backed by American labor laws.


• It is delicious coffee.


• The farmers are not exposed to harmful pesticides, and neither is the environment.


• You can visit the farm yourself, or see pictures from tourists. I highly recommend visiting, though!

Otherwise, prepare to invest plenty of time reading literature about different biodiversity certifications or getting to know your local importer better than they may be comfortable with.