Visualizing Algorithms f

Algorithms are a fascinating use case for visualization. To visualize an algorithm, we don’t merely fit data to a chart; there is no primary dataset. Instead there are logical rules that describe behavior. This may be why algorithm visualizations are so unusual, as designers experiment with novel forms to better communicate. This is reason enough to study them.

But algorithms are also a reminder that visualization is more than a tool for finding patterns in data. Visualization leverages the human visual system to augment human intellect: we can use it to better understand these important abstract processes, and perhaps other things, too.

This is an adaption of my talk atEyeo 2014. A video of the talk will be available soon. (Thanks, Eyeo folks!)


Before I can explain the first algorithm, I first need to explain the problem it addresses.

Van Gogh’s The Starry Night

Light — electromagnetic radiation — the light emanating from this screen, traveling through the air, focused by your lens and projected onto the retina — is a continuous signal. To be perceived, we must reduce light to discrete impulses by measuring its intensity and frequency distribution at different points in space.

This reduction process is called sampling, and it is essential to vision. You can think of it as a painter applying discrete strokes of color to form an image (particularly in Pointillism or Divisionism). Sampling is further a core concern of computer graphics; for example, to rasterize a 3D scene by raytracing, we must determine where to shoot rays. Even resizing an image requires sampling.

Sampling is made difficult by competing goals. On the one hand, samples should be evenly distributed so there are no gaps. But we must also avoid repeating, regular patterns, which causealiasing. This is why you shouldn’t wear a finely-striped shirt on camera: the stripes resonate with the grid of pixels in the camera’s sensor and cause Moiré patterns.


This micrograph is of the human retina’s periphery. The largercone cells detect color, while the smaller rod cells improve low-light vision.

The human retina has a beautiful solution to sampling in its placement of photoreceptor cells. The cells cover the retina densely and evenly (with the exception of the blind spot over the optic nerve), and yet the cells’ relative positions are irregular. This is called a Poisson-disc distribution because it maintains a minimum distance between cells, avoiding occlusion and thus wasted photoreceptors.

Unfortunately, creating a Poisson-disc distribution is hard. (More on that in a bit.) So here’s a simple approximation known as Mitchell’s best-candidate algorithm.

▶ Play


You can see from these dots that best-candidate sampling produces a pleasing random distribution. It’s not without flaws: there are too many samples in some areas (oversampling), and not enough in other areas (undersampling). But it’s reasonably good, and just as important, easy to implement.

ROBOTS.TXT DISALLOW: 20 Years of Mistakes To Avoid f

The robots.txt was first officially rolled out 20 years ago today! Even though 20 years have passed, some folks continue to use robots.txt disallow like it is 1994.

Before jumping right into common robots.txt mistakes, it’s important to understand why standards and protocols for robots exclusion were developed in the first place. In the early 1990s, websites were far more limited in terms of available bandwidth than they are today. Back then it was not uncommon for automated robots to accidentally crash websites by overwhelming a web server and consuming all available bandwidth. That is why the Standard for Robot Exclusion was created by consensus on June 30, 1994. The Robots Exclusion Protocol allows site owners to ask automated robots not to crawl certain portions of their website. By reducing robot traffic, site owners can free up more bandwidth for human users, reduce downtime and help to ensure accessibility for human users. In the early 1990s, site owners were far more concerned about bandwidth and accessibility than URLs appearing in search results.

Throughout internet history sites like, the Library of Congress, Nissan, Metallica and the California DMV have disallowed portions of their website from being crawled by automated robots. By leveraging robots.txt and the disallow directive, webmasters of sites like these reduced downtime, increased bandwidth and helped ensure accessibility for humans. Over the past 20 years this practice has proved quite successful for a number of websites, especially during peak traffic periods.

Using robot.txt disallow proved to be a helpful tool for webmasters; however, it spelled problems for search engines. For instance, any good search engine had to be able to return quality results for queries like [white house], [metallica], [nissan] and [CA DMV]. Returning quality results for a page is tricky if you cannot crawl the page. To address this issue, Google extracts text about URLs disallowed with robots.txt from sources that are not disallowed with robots.txt. Google compiles this text from allowed sources and associates it with URLs disallowed with robots.txt. As a result, Google is able to return URLs disallowed with robots.txt in search results. One side effect of using robots.txt disallow was that rankings for disallowed URLs would typically decline for some queries over time. This side effect is the result of not being able to crawl or detect content at URLs disallowed with robots.txt.

What’s Up With That: Building Bigger Roads Actually Makes Traffic Worse f

Változnak a fogyasztói jogok az Unióban f

Life in the Atomic Do-ocracy f

Interface Vision f

Cost-Efficient Continuous Integration f

Layout in Flipboard for Web and Windows f

At Flipboard, we are working hard to build the world’s best personal magazine—a magazine made just for you, filled with the stories you care about most.

Magazine layout design plays a key role in telling those stories. Good layout design frames a story and impacts how you are informed by the content. For example, in the hallways of Sports Illustrated, editors hang up every page of the print edition to be reviewed and manually tweaked before publication.

When you read Flipboard, articles and photographs are laid out in a series of pages you can flip through, just like in a print magazine. Each magazine pagelayout feels hand-crafted and beautiful—as if editors and designers created it just for you.

How do we automate the whole process of layout design and editing? By slotting your content into custom designed page layouts—like fitting puzzle pieces together. We start with a set of page layouts created by human designers. Then, our layout engine figures out how to best fit your content into these layouts—considering things like page density, pacing, rhythm, image crop and scale.

In many ways, that is the key to Flipboard’s signature look and feel: at its heart are the work of real designers.

In the Beginning

In 2010, we built Flipboard Pages, a layout engine that turns web page articles into magazine pages for the iPad.

Flipboard Pages paginates content from world-class publications includingVanity Fair and National Geographic.

Pages can produce beautiful layouts, replicating the brand identity and custom typography of each publication. Pages used CSS3, SVG and vanilla JavaScript to make rendering as high fidelity and performant as possible on constrained mobile devices. (such as the original iPad running iOS 3.2) The download footprint for a publication’s layouts averaged around 90K for layouts, styling, fonts and nameplate images–lighter than the equivalent web page or a single photograph from an article.

A designer first creates a set of about 20 page layouts, divided up into portrait (768x1004) and landscape (1024x748) orientations. From this set, Pages selects the layout that best fits the desired content, inserts the content into the layout, and produces a final page. With this example-based approach, we rely on designers to make layouts clear, distinct and beautiful.

While Pages could create great layouts, they only worked at a specifically designed size.

Web and Windows 81 presented a new challenge: Users can resize browser windows to any size, at any time. To support arbitrary sizes, we needed something better.

Don't Help Your Kids With Their Homework f

A Day of Communication at GitHub f

How does Scooby Doo and the gang have enough money to travel the world and solve mysteries for free? f

The Asshole Answer:  It’s a cartoon, dumbass.

The Perverted Answer:  Velma and Daphne are call girls.  

The Stoner Answer: Shaggy is a pot dealer.

The Cynical Answer:  Shaggy is a pot dealer.

The Optimistic Answer:  Shaggy is a pot dealer.

The Businessman Answer:  Shaggy is a pot dealer.

The Practical Answer: The gang probably charges a fee for their services. 

The Real Answer: Shaggy is definitely a pot dealer.

Camera Develops Pictures With Algorithms, Not Lenses f

Do prices at $.99 instead of $1.00 result in more sales? - Quora f

This is called Psychological pricing and has been studied a lot by the marketers.…  

The concept was not invented by “Bata” as one of the other answers suggested, but has been in existence far before that - at least since  1880s. Here is a 130 year old ad [1]. 

Although the top answer claims a definitive history, the answer to the origin of this strategy is unclear. [3]  There are 3 different theories of its history:

  1. Marketers (such as RH Macy) of mid 1800s tried to ambush their competitors in highly price sensitive goods.
  2. Melville Stone of Chicago Daily News priced his paper at 1 cent. However, given that cents were not in common use then, he coaxed local shops into odd pricing so that his customers will have the pennies to spend on his paper.
  3. As Frederick Arciniegas suggested, it was a cash control mechanism due to the arrival of the cash register. 

Why do they continue to do odd pricing?

  1. Customers see odd numbers as correctly priced rather than whole numbers. They tend to think that a rational process is involved in the pricing and go with the pricing. On the other hand, with whole pricing, some customers perceive that they are being gouged.
  2. Odd pricing also sends a psychological cue that the good is priced to the lowest possible.
  3. In the earlier days, competitors in commodity products tried to gain more market share by pricing a penny or two lower than their competitors.
  4. Various researches indicate that customers are swayed more by the most significant first digits of a price tag and sometimes by the last digit. In one research done in 1997 they found that 90% of the prices end with either 9 or 5. However, as customers are subconsciously getting used to these odd prices, other companies like Wal-mart favor more of pricing ending with .98 to stay out of the crowd.

2. http://www.kellogg.northwestern….
3. http://marketing-bulletin.massey…

What can I learn right now in just 10 minutes that could be useful for the rest of my life? f

1. Primacy and recency : People most remember the first and last things to occur, and barely the middle.

When scheduling an interview, ask what times the employer is interviewing and try to be first or last.

2. If you work in a bar or in customer service of any kind…

…Put a mirror behind you at the counter. This way angry customers who approach you will have to see themselves in the mirror behind you and the chances of them behaving irrationally lowers significantly.

3. Once you make the sales pitch, don’t say anything else.

This works in sales, but it can also be applied in other ways. My boss at an old job was training me and just giving me pointers. I was working at a gym trying to sell memberships. He told me that once I got all the small talk out of the way and presented the prices, that the first person to talk will lose. It didn’t seem like a big deal but it actually worked. Often there were long periods of awkward silence as the person tried to come up with some excuse, but usually they bought.

4. If you ask someone a question and they only partially answer, just wait.

If you stay silent and keep eye contact they will usually continue talking.

5. Chew gum when you’re approaching a situation that would make you nervous like public speaking or bungee jumping.

If we are eating , something in our brain reasons ‘I would not be eating if I were danger. So I’m not in danger’. It has helped me to stay calm a few times.

6. People will always remember not what you said but how you made them feel.

Also most people like talking about themselves so ask lots of questions about them.

7. When you’re learning something new, teach it to a friend . Let them ask questions to you related to it.

If you’re able to teach something well, you can be sure that you’ve understood it very well.

Betteridge's law of headlines - Wikipedia, the free encyclopedia f

Betteridge’s law of headlines is an adage that states: “Any headline which ends in a question mark can be answered by the word no.” It is named after Ian Betteridge, a British technology journalist,[1] although the general concept is much older.[2] The observation has also been called “Davis’ law[3][4] or just the “journalistic principle”.[5]

Betteridge explained the concept in a February 2009 article, regarding a TechCrunch article with the headline “Did Just Hand Over User Listening Data To the RIAA?”:

This story is a great demonstration of my maxim that any headline which ends in a question mark can be answered by the word “no”. The reason why journalists use that style of headline is that they know the story is probably bullshit, and don’t actually have the sources and facts to back it up, but still want to run it.[6]

Five years before Betteridge’s article, a similar observation was made by UK journalist Andrew Marr in his 2004 book My Trade. It was among Marr’s suggestions for how a reader should approach a newspaper if they really wish to know what is going on:

If the headline asks a question, try answering ‘no’. Is This the True Face of Britain’s Young? (Sensible reader: No.) Have We Found the Cure for AIDS? (No; or you wouldn’t have put the question mark in.) Does This Map Provide the Key for Peace? (Probably not.) A headline with a question mark at the end means, in the vast majority of cases, that the story is tendentious or over-sold. It is often a scare story, or an attempt to elevate some run-of-the-mill piece of reporting into a national controversy and, preferably, a national panic. To a busy journalist hunting for real information a question mark means ‘don’t bother reading this bit’.[7]

Betteridge has admitted violating his own law (writing a question headline with the answer “yes”) in an article titled “Does the Mac App Store let you use software for commercial use?” published at his own site.[8]

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