Blog Archive

Every so often a Muslim friend contacts me saying they’re coming to visit Denver and would like to know which Halal restaurants they can visit. I decide to post the list of restaurants here, so I can share it easily and update it periodically.

I’ve been working on an app that requires users to upload data to a server, where the data is used to create machine learning models. The process to create a model takes a lot of time (as much as 3 minutes). I don’t want to have an HTTP request open for 3 minutes while the model is being created. I would rather the server accept the request, send back a response immediately, and queue the task for processing. Then the user can poll the server to see if their model is ready. I realized that Celery is the perfect tool for this. In this post I write about how I set up Celery and Flask and share sample code.

I have a table in a relational database (PostgreSQL) that contains time intervals. In this post I’ll show you how to find gaps in those intervals.

Sometimes the train called Opportunity slows down just enough to let you hop on—if you want—before speeding away. I hopped on.

After more than nine years on Twitter, I finally deactivated my account. I refuse to contribute to the success of any platform that promotes the hatred of the villainous Donald Trump. I hope Twitter CEO Jack Dorsey never has to face the persecution that the vile Trump is trying to inflict on people like me. However, if anyone deserves it for enabling hatred, it is him.

This is a guest article I wrote for the newsletter of a friend of mine who’s an Estate Planner.

Almost every digital or monetary asset you own is protected by a password. Some service providers, like investment brokers require multiple pieces of information, like your social security number, account number, date of birth, etc. These are all things that a provider assumes only you know. Once these secrets are known to others your asset is compromised. So in order to keep these secrets safe, you need to do two things: prevent others from being able to view these secrets, and prevent others from being able to guess them.

Another in a series of posts documenting my process of updating an aging app.

Another in a series of posts documenting my process of updating an aging app.

I noticed that the code coverage reports from XCode 8 recently started showing me coverage for .m files that were in the CocoaPods that I’m using. In this post I document how I fixed that.

How many Chicago motifs can you find here?

Mark Frimston found out something very interesting about the local time in the UK at UNIX epoch 0. Took me by surprise.

If you walk too fast, you might miss them. Two gardens flank the Art Institute of Chicago, on Michigan Avenue. Now, we all know Michigan Avenue as a busy, bustling street, but these gardens are great places to stop. And think. Or just clear your head before merging back into the fast pace of the sidewalk. This is the South Garden, looking back out towards Michigan Ave.

Several times in the past few months I have tried to add a post to this blog. But I couldn’t because of some obscure Ruby error whenever I tried to generate the blog using Octopress. There was so much friction in the simple act of adding a new post, that I finally decided enough was enough and moved the blog to Pelican.

Well, that was fun. For the first time ever I wrote a blog post every day for a month. Here’s what I learned:

Mastering something can take time. In my case, it took me about 18 months to get to the point where I could do a set of 10 Lever Pull-ups.

A few weeks ago, when my older two boys were getting ready to go off to college I was reminded of something I read online: Buy a toilet plunger before you need a toilet plunger. In today’s post I would like to list four things that you should know how to do, before you have to do them.

A few minutes ago I zoomed in on a photograph that I had taken in April. I saw details that fundamentally changed my understanding of what’s going on in the picture. It’s funny how often that happens.

My family visited the city of Medina in Saudi Arabia last year. One night, while we were out, everyone was tired and hungry. They found a comfortable spot and decided to sit down for a while. They asked my older sons and I to go pick up some food from any local restaurant and bring it back, so we could all eat together.

If you’re a parent, you’ve either been through this, or will soon: At some point you stop being known by the neighbors by your own name, and start being identified by your kids’ names. You become “Adam’s Dad” or “Sarah’s Mom.”

Some of you may not have room on your hard drive to back up your iPhone. This short post shows you how I backed up my iPhone to an external drive (on a Mac).

Every Monday, Wednesday, and Friday I have been posting different pictures of doors that I saw in Dublin. When researching one of the buildings I was surprised to learn of the connection between a house that James Joyce visited (and wrote about) and Tipu Sultan, the ruler of Mysore.

As I child I read a lot of European stories like those from the Brothers Grimm or Hans Christian Andersen. As I’ve grown older I’ve come to realize that if there were one story I would want to make sure I share with my children it would be “The Emperor’s New Clothes.”

Fourteen days in India. Traveling with a tripod. Used it for only one shot. Totally worth it.

I’d like to share with you the way I teach optionals in Swift. I’m pretty sure I’m not the first person who thought of this method, but since I haven’t seen anyone else write this up, I’ve taken it upon myself to do so.

Is it ever a bad idea to sign your name on good code that you write?

Different people have different gifts. Some excel at their profession, others are talented at various arts, while yet others are blessed with strength or wealth. Once you know what your gift is, it’s time to consider using it to help others.

One of the most beautiful places I visited during my recent trip to Dublin, Ireland was the Trinity College Library. The long, two-storey high grand hall with stacks on each side was breathtaking. The smell of old books filled the air.

I had been taking the same path to work for the past ten years. Sure, there were minor variations - I could turn this way a block earlier, go that way a block later - but essentially the walk was the same. I started recognizing the people I’d see on the street (and secretly naming them in my head), the doors on buildings, and even the various imperfections on walls and on sidewalks. I am an amateur photographer and, in a word, I was bored. On a typical walk to and from work, I could look at anything and feel I knew every visual facet of it. Leisurely photo walks were always different, but were few and far between. And then, I moved to a new job.

Today’s post is a quick story. In 2009 I took my kids hiking in Wisconsin. It was the first time the kids had gone on a long hike. I assured my wife that we’d be fine and we left after their regular Saturday activities. It was a character builder for all of us.

The only certainty in life is that it has an end. I’ve been trained to think of death as a sad, morbid topic. But lately I’ve come to realize that embracing the inevitable can have a markedly positive effect on my life.

This is one of my favorite things about the Workout App on the Apple Watch: the ability to start a workout without having any specific goal in mind.

I love that I can just start and see where the workout takes me. There’s no pressure reach a certain time or calorie count. I can just play it by ear.

See you tomorrow.

This has been eating at me for the last 28 years. I’d like to start talking about it today. It’s what I call the American mantra of “I have no regrets.” In this post I’ll lay out my initial thoughts so that I can, over time, flesh them out and come up with a well-written essay.

We’ve all heard or seen the ads making claims like, “Download our scientific app and play our brain games! They’ll improve your memory and actually improve your brain power over time.” I’d often thought about downloading one of those apps and trying it out. Wouldn’t hurt right? Wrong. It would hurt your pocketbook, but wouldn’t help your brain at all, according to Johns Hopkins Professor of Neuroscience David Linden. What would help is exercise, he tells Terry Gross, of NPR’s “Fresh Air”.

I was pre-teen in the early 1980s. The 1980s was the decade of the Rubik’s Cube. It was everywhere. I was in India at the time, and people over there were as nuts about it as people in Europe and the US. Kids all over the world were experiencing the thrill of solving it. But not I. I had a book that described how to solve the cube, but it did a really poor job of describing the seemingly arbitrary algorithms required. Even though I could solve a single side by myself, I couldn’t solve the entire cube without having the book open in front of me, following its complex directions.

Today’s post will be short and sweet. I want to share something that worked for me really well when I recently started my new job. There are a few existing iOS products for which I will have to become the primary developer. I needed to come up to speed on these products quickly. I started of the way we developers normally do: read internal documentation, examine the Main.storyboard file, look at the AppDelegate.m file. But then I got a good idea. I asked the salespeople to demo the product to me, as if I were a prospective customer.

Humans have been using rope as a tool for thousands of years, even before we started recording history. Knots and rope-tying is one of the few technologies that have persisted essentially unchanged in all of the known human history. This is the second in a series of posts about the most important knots. The bowline knot is certainly in the top two or three.

I’ve been working out regularly since I was 16 years old. But it’s only in the last ten years that I’ve really learned how to do it right (for me).

Someone asked me if I wanted to work for them this morning. But they did a really poor job doing it.

We can watch football players literally kill each other for our entertainment. Or we can choose not to. It’s time to boycott the NFL.

It can be difficult to leave a job and start working at a new place, especially if you like where you work right now.

When you have to execute SQL statements inside large loops, you may find that your app slows down considerably. In this post I show you one way of improving the performance of your app when database access is the bottleneck.

These are notes that I took while trying to find the optimal Apple Watch settings that maximize my battery life.

One of the best portraits I’ve taken is a picture that I took quite by accident as I was calibrating my camera for a future shot. This is the story behind that picture. If you know the subjects, please have them get in touch with me, so that I may give them this photograph.

Travelling often gives you the opportunity to take unusual pictures of street scenes. In this post I describe three pictures I took of the same scene, and how a small change in the third (completely out of my control) changed the picture from a good one to a great one.

Zipping through the streets of Bangalore in an auto rickshaw.

When working with something dangerous, you must always ask yourself, “If the forces that are maintaining the current equilibrium give way, what’s the worst that can happen?”

Now that I’m starting a new iOS development project, I’m trying to have close-to-complete test coverage of critical parts of my code. I’m using XCTest pretty extensively, and found that I needed to test a rather complicated private method that is critical to my app’s user experience. This post shows you how I did it.

People of conscience all over the world have been watching with horror as Israel continues its bombing and shelling of civilians in Gaza, seemingly intentionally targeting children and defenseless civilians. Despite feeling powerless we want to do something to help the people there, and not merely watch them being massacred. As Muslims we know we’re supposed to materially help those in need as well as pray (make du’aa) for them (as well as other places like Syria and Burma), but sometimes it gets difficult to find a balance between action and prayer. This article, based on notes from various lectures I attended during Ramadan, attempts to help people like me find that balance.

As an amateur photographer I’ve found it hard to find information on how to use external flashes with the Fuji X100S camera. In this post I’ll show what I did to get it to work and how I used a Fuji with two external Nikon SB-800 flashes.

I like how the rays of the sun reflected off the train. I only had a second to take this picture as there was a crowd of commuters right behind me.

Imagine, for a minute, that you’re an astronaut. On the ISS. Conducting a space walk. There you are, outside your vehicle, and you realize your spacesuit is leaking. You could drown. In outer space.

I recently needed to issue several dozen HTTP DELETE REST API calls of the form http://www.example.com/blah/n where n was a sequential version number. In this post I’ll show how to do this easily from the command line.

This photo was taken in ‘stealth’ mode: shooting from the hip, no audio, no display on the rear LCD. I had no idea what the composition would look like.

First

This is an Oak tree that I planted in my front yard about five years ago. I’m glad it’s survived all the storms we’ve had since then. I hope to see it grow into a Mighty Oak.

Here are the slides and links from my recent Blitz Talk on password security at SecondConf.

The 2011 MacBook Air is my primary machine now. The SSD and CPU are fast and the machine seldom slows down when I have many apps open.

The Lower Antelope Canyon in Page, Arizona is a place of breathtaking beauty. Located in Navajo country, it’s best viewed at around noon when the angle of the sun’s rays makes for very dramatic lighting.

“Cloud Gate” - fondly known as The Bean. Millennium Park, Chicago. Looking East, half an hour before a sunrise that was hidden behind clouds.

Now that I’ve been using Pinboard for a while, I find myself having to search for one bookmark or another quite often. I grew weary of going to my Pinboard page, clicking on the search box and entering my query. Here’s how I streamlined it in Chrome.

As you’ve probably noticed I’ve modified my Octopress installation so the color theme is light and minimalistic. Since some of you wanted to know, here’s how I did it.

What follows was originally posted by me on my Facebook wall. Since the message resonated with many people I’m moving it here so it can live on the public Internet.

I love word games. I’ve played Scrabble on my iPhone more than 1200 times. Then, a couple of weeks ago they changed their user interface. Now I’m afraid I’ll never play it again. In this post I’ll tell you what I don’t like about the changes, and how I plan to avoid similarly alienating users of my own apps.

In 2010 I made my own Wing Chun Kung Fu Wooden Dummy. The Wooden Dummy is a training tool that helps you practice the fighting techniques of Kung Fu. This post explains how and why I built it.

I recently needed to upgrade one of my machines to mod_perl 2.0. I encountered many problems on the way, and would like to share with you what I did to finally get it to work.

I’m currently in the last 48 hours of my first ever visit to the Grand Canyon in Arizona. Just hours before setting out to see the Canyon for the first time, I realized that I couldn’t recharge my camera’s battery. I had 80% of a full charge, and four more days of vacation to go. Time to panic?

After only being able to do a single one-legged medicine ball burpee last week, I was able to do 12 last night. Here’s the trick:

In this post I’ll show you how I added tag clouds to my Octopress blog.

There have been times when I’ve had to extract a particular column from a tab-separated or comma-separated file. The best way to do this is to use the shell command cut. Let’s say I have a file named input.txt that looks like this:

Over this past weekend I switched my blog over from WordPress to Octopress. In this post I write about why I did it, what exactly I did to get the blog just the way I wanted, and what I plan to do in the future.

A key aspect of good photography is exposure - the amount of light that enters the lens.  One of the most useful tools a digital cameras has to help you measure a photograph’s exposure is the histogram. In order to learn how to use it, you must first learn understand what a histogram is.

Let’s pretend I teach a class of 20 students. One day I decide to give the students a test in which they can score anywhere from 0 to 100 points.  After grading the tests I want to see how the population of students did.  So I graph the scores in a histogram. A histogram displays the distribution of measured values across a population.  Let’s make one now.

Let’s say you have two text files, FileA and FileB.  You want a file that has all the lines of FileA that are_ not_ in FileB.  How do you do that?

The simple answer is grep. The -v option inverts the search, and only prints lines that do not match.  The -f option is used to specify a file that contains a list of all the patterns for which to look - one pattern per line.

I’m trying to formulate a sensible strategy to overhaul my net presence. The rough plan so far:

• Change my 12-year-old email address that is on every spammer’s short list
• Extract friends’ contact info from Facebook
• Delete Facebook account.
• Import FB contacts into Google & Mac
• Redirect facebook friends to current tech blog (aijazansari.com) and new personal blog.
• Find out if FB friends can subscribe to an RSS feed of my blog somehow (doesn’t seem possible any more)
• Pick up the phone and actually talk to friends more often.

The goal’s pretty obvious - I want to reclaim my data.  I think I own my relationships, not FB, not Twitter, and not Google+.  So far, G+ may be the most accommodating network out there - if I can export my G+ presence as easily as I can export my G+ contacts, we might have a good candidate here.

If you have any ideas or comments or experience with this, please let me know.

I’ll keep you posted.

Update 2012/06/30

Like so many of you, I’ve given up on Google+. Most of the people I wanted to communicate with never made the switch. In the end, having those lines of communication open with my friends was more important than the platform. G+ has been dismissively called a “Ghost Town,” and in my case, at least, that wasn’t too far from the truth.

Fire marks were used in the 1700s to designate homes or buildings protected by the fire insurance companies. They were generally oval plates placed on the outside of a structure to let volunteer fire brigades know which buildings carried a “reward” if saved.

I hadn’t really given much thought to how the iPhone handles scrolling until I recently had to implement it myself. I needed to add vertical scrolling to a UIView that models a real-life metaphor. In my particular case I feel using a UIScrollView would break the metaphor - the user would “snap out” of the immersive app and realize they’re merely using an iPhone app with a pretty skin. So the natural solution was to implement scrolling myself. This is how it went from simple, unnatural scrolling to its current state of acceptable inertial scrolling.

Yesterday I started learning how to write applications for the iPad and the iPhone.  There are so many books that promise to teach you everything you need to know that picking one or two (or three) can be very difficult.  While I normally like to learn new skills by reading a good book, I think for iOS development a more dynamic source would be a better choice.

When I recently switched from the iPhone to HTC Evo running Android, I found the Evo’s Alarm Clock app surprisingly primitive.  When I had multiple alarms set, it wouldn’t sort them by the time of day.  Predictably, I started looking for alarm clock apps online, but the others were even more primitive.  One was so bad that once the alarm went off, there was no way to turn it off other than rebooting the phone.

When you’re working in Unix or Linux or even Mac OS X, there are often times when you need to apply the same command to a list of files.  In this post I’ll show you a couple of quick ways to do this using the bash shell.

A few day ago the data center where I used to host my name servers lost its connection to the Internet for a very long time (almost 36 hours).   Whatever the cause, the web, mail and application servers of customers big and small were dead in the water.  There was no way to reach them via the Internet.  The data center’s owner, who’s a friend of mine, was on the phone with his service providers, getting the issue sorted out.  In the first 24 hours I sent him around five text messages and was able to speak with him a couple of times. However, many of his other clients couldn’t reach him, and some of them even called me asking if I knew what was going on.

I remember in my first Computer Programming class in college, the instructors wanted to make sure we understood the concept of persistence by saving application data to disk.  To keep things simple we would serialize data and save it to text files.  Once we learned advanced concepts we migrated to using relational databases.  As a professional, most of the apps I see use an RDBMS like DB2, PostgreSQL, Sybase or Oracle.  Text files have been relegated to the simple homework assignments of Programming 101.

There are, however, many classes of applications for which text files are the preferred means of storing data.  One of the main reasons is that when data is stored in a relational database, editing it is not a trivial task.  A well-normalized database is not easily updated via an SQL command line.  More often than not, a dedicated, graphical editor is needed to model the complex relationships.

Humans have been using rope as a tool for thousands of years, even before we started recording history.  Knots and rope-tying is one of the few technologies that have persisted essentially unchanged in all of the known human history.  As you can imagine, there are different knots for different applications, and in this series of posts, I would like to share with you the knots that I’ve found most useful both at home and outdoors.

I had this dilemma a few days ago: I had taken almost 4,000 pictures during a vacation 12 months ago. The vacation was in Asia (two continents over), and the time on my camera was wrong. I was importing the pictures into Adobe’s Lightroom, and wanted them to have the correct time just in case I wanted to know when in the day certain pictures were taken. I thought of looking for pictures taken during sunset, and then using solar calendars to figure out when sunset was at a certain landmark on a certain day of the year. But then I had a better idea:

One of my favorite activities in spring, summer and even early autumn is sitting outdoors by a campfire.  For safety reasons, outside my home I can’t make a campfire on the ground, so I use a standalone fire pit.  The older children, as well as my nephews and nieces like learning how to start a campfire without matches.  I usually use metal and flint.

When I first started dabbling in woodworking at the age of 15, the only tool I used to cut wood was an old, rusted woodsaw.  Every cut would start straight and true, but as I’d push the saw deeper into the wood, it would buckle and warp, my arms would get tired, and the cut would stray from the line.  A few years ago I learned about pull saws and once I started using them I have stuck with pull saws for all my manual wood-cutting tasks.

As of this past weekend it’s been fifteen years since I started my career as a software developer.  With the exception of a few months here and there, I’ve spent all these years working on Linux or Unix-like operating systems.  I’ve noticed that despite the wide variety of tools and applications I have used and continue to use, some key skills are always in demand in this field. One of these is mastery of a text editor.

This is the first in a series of blog entries on photography.  Today we look at one of the most critical parts of any camera - the lens.

Have you ever noticed that people can run faster on flat ground than on sand or water?  It’s the same way with light.  Light travels faster in air than in glass.

This boat looked out of place on the Khalid Lagoon by the Al Buhaira Corniche in Sharjah. It was too small to be a water taxi, and too drab to be for tourists.  As I approached it, I realized that its purpose was to pick up all the garbage floating in the lagoon.  It was full of soggy plastic bags and other detritus.  I’m glad I wasn’t close enough to smell it.

This picture was taken on my walk along the Sharjah Corniche on January 6th 2010, shortly after dawn.  I framed my shot carefully, right in front of the minbar, to exploit the symmetry of the building.  As I clicked, I noticed a blur as a cyclist strayed into my shot.  I had just enough time for one more shot before he left, and this second shot is what you see here.  I think the lucky addition of this man into the frame makes this a better shot than the one I was planning.

1/50 sec at f/4.5 :: 22mm focal length :: ISO 400

Last night my Macbook Pro would not wake up from sleep. After jiggling the mouse and hitting the space bar a few times I powered it down. I powered it back up, and I could hear it booting up, and could feel the hard disk move, but there was nothing on the screen. After a little Googling I suspected the video driver was dead.