Gran Fondo

Posted on May 19, 2013 by Jeff Mather

I was hanging out in the middle of the pack about 85 miles into the North Shore Tour de Cure “gran fondo” feeling a bit out of it. I was hanging on to the rider’s wheel ahead of me, but it felt harder than before, and I could hear the world buzzing around me.

Losing my background noise filter frequently is a sign that my blood sugar is going low. I had been hanging out around 200 most of the ride, but I gave myself a minuscule amount of insulin at the previous rest stop since I hit that magic number where, even on a ride, I feel like I need a little something extra to help my body use the food that I’m giving it. Actually being low seemed unlikely, but I’ve seen my blood sugar move a lot in a short amount of time before. If we weren’t going so fast and riding so close together, I would have checked my BGs, but I worried about popping off the back of the pack and being caught in no-man’s-land. Plus, I didn’t really think I was low.

It was also entirely possible that I was at my limit, with or without diabetes. We had already gone 25+ miles farther than my previous longest ride of the year. I’m a firm believer that if you can ride sixty miles, you can ride 100 miles; it’s just a matter of how fast you can go and how you feel at the end of the day. I could go 100 miles for sure, but how was it going to feel? Early on, I realized today was going to be different than my Tour de Cure century last June, which was a leisurely gabfest and sightseeing jaunt with Scully. Unlike that ride, at the eighth mile of this ride there was a two-mile time trial that showed that the people I was riding with weren’t afraid to throw down. In fact, it felt just like triathlon, except faster and without my tri bike. (I kept thinking, “Well, there’s a drafting violation,” before remembering that it was okay today.) About a half-hour later, when heading out of the first rest stop, I managed to get on to the front of the pack and drag everyone five miles to the start of the timed hill climb. Needless to say, it wasn’t my best effort.

That categorized climb was 55 miles earlier. Since then, we had ridden almost another three hours, averaging just under 20 miles per hour (32 km/h). I spent those three-ish hours watching the rider ahead of me—taking care to stay close (but not too close) to his wheel—and checking the road for hazards and turns, which I pointed out like a good pack rider. During those 55 miles I worked on using just the right amount of energy to stay close to the person ahead of me without overdoing it and needing to move out of their slipstream to slow down or (horror!) touch the brakes and then pushing hard to stay on their wheel when I relaxed too much. Power up; power down; power up; power down. And then throw in a hill to cause a ripple through the pack as we all stood up and seared our quads to keep up with the person driving the pace. [1]

I was struggling a bit, but I didn’t want to be that guy. This was a Tour de Cure—which nominally meant that it was a ride to help people with diabetes—but most of the people in the gran fondo were treating it as just another organized ride. Unlike last year’s ride, there were many fewer Red Riders on the long ride, and most of the people we passed didn’t give the typical “Go, Red Rider!” cheer. No one asked anything about diabetes, and when I asked what people’s connections were to diabetes, the answers were vague and almost apologetic. [2] I was torn between wanting people to understand how difficult diabetes can be sometimes and how much people without diabetes take for granted and not wanting to use diabetes as any kind of excuse for anything unless I’m actually in a hypo-induced stupor. I was determined to be the strongest guy with diabetes on the ride and to challenge any lingering misconceptions about our abilities.

So when we rolled into the last rest stop fifteen miles from the finish, I tested my blood sugar, saw that it had dropped more than 80 mg/dL (4.5 mmol/L), ate four glucose tablets and a PB&J sandwich, and mixed some Skratch mix into my water bottle. I wasn’t hypoglycemic, but I had dropped enough (as I had suspected) to feel it and to need to prevent falling at the same rate for much longer. I put another banana into my back pocket to replace the one that I had bobbled and almost caught before losing it at 30 mph earlier in the ride. I took a quick picture with my camera for posterity and then headed out with my adopted group.

A few miles later I was feeling back to my perky self. All of the work I had put in so far was still dragging on me, but I noticed that the miles seemed to tick down a lot faster than just a bit earlier. We also started passing a whole bunch of Red Riders now that all of the routes were sharing the same road near the finish. One of the guys from the small Blue Cross Blue Shield team rolled along side me.

“Hey, Jeff. How would you like to lead us all in when we cross the finish? I mean you’re a Red Rider, and it just seems right.” I was genuinely touched, and the message rippled through our now much smaller group of about a dozen riders.

I knew that if I was going to lead people in I was going to make sure that I did a pull on the front so that it wasn’t just a ceremonial gesture. The last three miles were great! I put my head down and churned out a consistent 20 mph pace, just slightly faster than our 19 mph (31 km/h) pace for the entire ride. My body felt the best that it had all day. When we were stopped at the intersection just before the finish line waiting on the police officer to stop traffic for us, there were compliments and handshakes all around. I like to think it was because I survived their out-for-blood, keep-up-or-ride-by-yourself club ride, instead of just having a really good pull for a guy with diabetes.


1 — I need to more of these hardcore training rides. I think it would make me a much stronger rider. [back . . .]

2 — There was a whole lot of “My mother-in-law/father/aunt had diabetes.” Always in the past tense. Some of the people I talked to were (admittedly) a bit older, but many were my age or younger. Clearly, there’s a need for much better information about diabetes and how to live with it successfully so that there’s less past-tense and more present-tense. And there’s also a tremendous need for research funding and advocacy so that there are more people living without diabetes. And that, dear readers, is why I was at today’s ride. [back . . .]

Posted in Cycling, Diabetes | Leave a comment

Shhh…

Posted on May 18, 2013 by Jeff Mather

I should be writing today’s Diabetes Blog Week post about my ultimate diabetes device, but I really need to go to bed in a few minutes. Tomorrow I’m leaving Milford around 5AM to drive an hour to the start of the North Shore Tour de Cure Gran Fondo. “What’s a gran fondo?” you ask. It’s like a race but not. It’s a mass start event with some timed segments, but it’s not a race, okay?. Okay. I certainly won’t be racing the 100 miles . . . except for the hill climb and the time trial.

But don’t worry. I’ll post about diabetes doodads soon. And the ride of course.

Posted in Cycling, Diabetes Blog Week | Leave a comment

I Want that other Kind of “Diabetes”

Posted on May 17, 2013 by Jeff Mather


Diabetes Blog Week gets a little freaky this Friday . .  and frankly a little uncomfortable if taken seriously. “If you could switch chronic diseases, which one would you choose to deal with instead of diabetes?”

Comparing chronic illnesses and wishing that you had a different one is a fool’s bet. At worst, you show yourself as failing to understand how difficult another person’s illness is. At best, you still have a chronic illness! You will still need to take medication or be watchful and worry about when your illness will turn more serious.

Instead, I’d rather have the kind of diabetes that some people think I have. No, I don’t mean the diabetes that people believe means I can’t eat delicious things with sugar. Nor do I mean the one that leads people to think there are things in my life I can’t or shouldn’t do. And it’s certainly not the kind of diabetes that somebody’s aunt “who didn’t take care of herself” had before she went blind, lost her feet, became impotent, had a heart attack while on dialysis, and died. (All of those things are no laughing matter, of course, and can happen to anyone, no matter their A1c.)

No, I wish I had the “easy” diabetes. That’s the kind of diabetes where insulin is a cure, where having a pump means that I can do and eat whatever I want without worrying about anything, where using CGM lets me test my blood just once a day, and where “following the rules” puts my A1c instantly into the non-diabetic range. It’s the kind where following a low-carb diet, making out with Halle Berry, or eating cinnamon makes your symptoms completely disappear. It’s the kind of diabetes where simply preparing a few recipes from a “diabetic cookbook” is enough to ensure perfect glycemic control. It’s the same kind that is already cured in mice, and the same cure would be ready for me in less than five years. This diabetes uses technology and medication which are so inexpensive, easy-to-use, and reliable that the artificial pancreas is a flawless cure. It the kind of diabetes where islet cells are readily available for transplantation, anti-rejection drugs are foolproof, and medical professionals and drug companies provide everything pro-bono.

Obviously, this “diabetes” doesn’t exist at all, but, believe it or not, I’ve actually heard or read all of these things before. It sure would be nice if any of these were true, though. Some of them may eventually come to pass; I really do hope so. Others—like making out with an Oscar winner—probably will be just as mythical as any kind of “easy diabetes.”

So, I’ll be keeping this chronic illness instead of trading it for another. Besides, I have plenty of work left yet to figure out this one.


p.s. — Just in case you missed it, when talking about a mythical, nonexistent “easy diabetes,” I certainly don’t mean type-2 diabetes. That variety is just as hard in its own way as any other chronic illness. Don’t forget what I said in the first paragraph.

Posted in Diabetes, Diabetes Blog Week | 1 Comment

Biggest accomplishment? No big deal.

Posted on May 16, 2013 by Jeff Mather


Today’s Diabetes Blog Week posts encourage us to “share the greatest accomplishment you’ve made in terms of dealing with your (or your loved one’s) diabetes.”

I won’t lie, my biggest accomplishment with diabetes is still a work in progress. It’s taken a long time to get where I am with being comfortable with insulin, and I could be even more comfortable with seeing a bolus wizard suggestion and just saying, “Okay. I can handle that amount of insulin without worrying.” Nevertheless, where I am now is much better than where I was a year ago . . . or even six months ago.

The results of “doing what I’m supposed to do” are encouraging. My A1c is the lowest I’ve had in quite a while, and I’m seeing fewer big spikes than in the past. I’m snacking less at times when I really don’t want to. Cycling with “normal” BGs is happening more often. Even eating Indian food is easier.

I am, however, having more lows than in the past and needing more (legit) snacks to prevent them, so I have some fine-tuning left to do. However, unlike in the past, I’m not treating those lows as a frustrating justification to do whatever. The changes I need to make are all do-able (By the way, I wasn’t simply flailing in the past; I was actually trying to make things better, but it was just a little hard to do that when I was adding so many other variables into the mix.)

Basically, this accomplishment is all about gaining the confidence I had needed to empower myself to do “scary” things (like taking insulin) and to enable doing more exciting things (like getting CGM no-hitters and doing half-Ironman triathlons).

Posted in Diabetes, Diabetes Blog Week, Life Lessons | Leave a comment

Presentation Titles

Posted on May 16, 2013 by Jeff Mather

I’m trying to help a coworker come up with a presentation title for a conference later in the year. We want a fun title which is also relevant to image processing. Part of me wants to work in the phrase “256 Shades of Grey.” We shall see.

Posted in Fodder for Techno-weenies, General | 1 Comment

Remembering the Desert

Posted on May 15, 2013 by Jeff Mather


Memories are the focus of today’s Diabetes Blog Week posts.

Until recently, my most memorable day with diabetes would have been the day of my diagnosis 13+ years ago. It was such a life-changing event—cleanly separating my memories into before and after—that it’s going to be hard to ever truly forget much of it. But recently more and more exciting/interesting/unusual things come to mind first when I think about diabetes and my life. On the bizarre side, I called Minimed from a pay-phone in the middle of the outback in Australia when my pump died. Later on that month-long trip, Lisa and I had a fabulous time snorkeling (sans pump), and I barely worried about diabetes at all.

Perhaps my most memorable diabetes event (at least for now) is last year’s JDRF Ride to Cure Diabetes in Death Valley. Diabetes was everywhere on this ride (including some of my favorite people with diabetes) and yet my diabetes was remarkably well behaved. The more time that passes from this event, the more special it becomes. I mean, I rode 105 miles in the desert Death Valley! It was hot and difficult and so meaningful. It’s something I couldn’t have done on my own, and all of the help from the volunteers and donors meant so much to me. That particular ride is not necessarily something I’ll ever do again, but the memory changes how I think about diabetes and what I can do with it.

Posted in Cycling, Diabetes, Diabetes Blog Week | 1 Comment

Cats: The Perfect Diabetes Service Animal

Posted on May 14, 2013 by Jeff Mather


Today, the second day of Diabetes Blog Week, prompts us to think about petitions for diabetes. (For some context on why this is relevant to the community, read the DiabetesMine article.) I’m not really a big fan of petitions, so I’m going to do one of the wildcard topics: “What is the ideal diabetes service animal?”

I’m going to have to go all-in here and say, “Cat.”

Let’s look at all of the reasons:

  • Cats are furry . . . and warm . . . and affectionate. It’s hard to do better than a warm, furry, affectionate critter that wants to be around you.
  • Cats—like diabetes—interrupt what you’re doing to remind you of their existence. This presents a very convenient reminder to test . . . especially at 3:30 in the morning when they pounce on your feet or walk all over your face.
  • They don’t really care what the hell you do as long as you feed them. They give you that look which says, “Hey. That thing looks bolus-worthy. I’m not going to judge you if you eat it.” Or maybe it’s a look of disapproval. Or ennui. It could definitely be ennui. Cats are an emotional Rorschach test.
  • With their constant desire for food, cats provide a reminder to eat that food you pre-bolused for.
  • Cats don’t bark or need baths. They’re pretty self-sufficient.
  • Cats are easily distracted by empty boxes. Need a diabetes break? Just set out an empty box, and voilà!

Well, that’s pretty much it.

Posted in Diabetes, Diabetes Blog Week, Photography | 5 Comments

The Truth Comes Out

Posted on May 13, 2013 by Jeff Mather


It’s here! Diabetes Blog Week has arrived again, and it’s time to let someone else help me figure out what to write about here. Today, we pretend that our health care providers are reading what we write. What would we want them to know (or not know) about our lives with diabetes?

Hey there, Awesome Endo and Awesome CDEs! I think y’all are pretty great. You have a really good sense of what people with diabetes are going through, and I believe you really treat this as a calling to help make our lives better and not just a job. I’ve shared links with you in the past, so there’s an outside chance that you are, in fact, actually reading this right now. But you’re all very busy people with lives outside of the office, so I kinda doubt that you actually are. Anyway.

What I hope you do see is also what kinda wish you wouldn’t see: People with diabetes are constantly doing things and making choices that are contrary to what we talked about in your office. We present you data that often doesn’t have all of the context. “What happened here?” Well, it’s a long complicated story that started earlier in the day . . . or the day before . . . or all of those years ago when I was on NPH. But really, that’s a lot more detail that I suspect you really want—or that I can remember—so I’m going to make an educated guess. (This probably isn’t surprising to you.) So many of the choices we make are “messy” and nothing like the ones that we talk about in the office.

Neither of us is doing anything “wrong”—whether it’s making suggestions based on limited data or living in a way that leads to such choices—but it makes it hard to feel completely honest during the conversations we have where we’re trying to make things better. This is part of the reason why I’m glad that you look the other way at the occasional highs and lows in my logbook. Don’t get me wrong; I’m doing my best to make the right decisions, gather the right data, and do the things we talked about. I’m just really glad that you don’t see the imperfections as failures, because I do enough of that on my own. (Although, I’m getting much better at being okay with those misses.

So, thanks for reading and for helping me be the best human pancreas I can be.

Oh! And I wish I could always show you CGM reports like the first picture below; but, really, they’re more often like the second one.

 


If you are a health care provider, be sure to read Céline’s post today.

Posted in Diabetes, Diabetes Blog Week | 1 Comment

Swim. Swim. Run.

Posted on May 12, 2013 by Jeff Mather

There’s just no getting around it: Today’s NE Season Opener triathlon was wet. After what felt like the longest time away from triathlon—August’s 70.3 was my most recent—I had been looking forward to this race for quite a while. It didn’t occur to me until yesterday evening, when we were watching the weather forecast on TV, that it was possible that we would get rain during the event. But rain it did. Sprinkles at first and then a full downpour during the bike portion. There were rivers running down the highway, and Lisa said there were several crashes on the big hill leading to the transition area. Fortunately, the rain ended right as I started my bike-run transition, and I finished with a time that was just off my best time from last year: 1:09:47.

I made a couple of good decisions today. First, I decided to bring Tommy V (my road bike) instead of Chrissie (my tri bike). Over open ground, Chrissie is a couple of miles per hour faster, but I’m a lot smoother and much more agile when out for a ride with Tommy. Given that I could barely see through the rain today and that some of the corners were tight, it was the right choice to pick conservatively. And yet I still was passing lots of people. In fact, my bike split felt good and was the strongest part of the event for me. I started to wonder whether I was pushing too hard given how many people I reeled in, but I had more than enough in the tank for the run. My other good decision was bringing a plastic bag to put my running shoes and socks into to keep them (mostly) dry until I needed them.

On the other hand, I should have started farther forward in the swim. Evidently, I got faster over the winter, and I was constantly swimming onto people, slowing my forward progress. I could easily have been about 10% faster if I’d had fewer people elbowing me in the face or slowing down in front of me. On the plus side, I drafted on the swim! That was a first, and it was pretty cool.

My diabetes mojo is a bit rusty. I decided to try something different today, so that I could eat a bit more before the event. I was doing pretty well keeping my BGs down until just before the start when it started to go higher. Unfortunately, I went all the way up to 274 mg/dL (15.2 mmol/L) by the finish. Something to work on for next time.

It’s good to be back!

Posted in Cycling, Diabetes, I am Rembrandt, Photography, Reluctant Triathlete, Running | 1 Comment

Crash and Burn

Posted on May 10, 2013 by Jeff Mather

Like a Sunburn: Two Mondays ago I had this conversation with my general practitioner.

“A few weeks ago I was sick, and then, a week after feeling better, I started having some pain in my leg. It felt as if all of my hairs were going the wrong way. Or as if my thigh had been scrubbed with steel wool. Everything on the left side of my body from my tailbone around my hip to just above my knee feels raw.”

“Kind of like a sunburn?” my doctor asked.

“Exactly, except that when I touch it or apply pressure it feels better. In fact, I feel best when I’m wearing bike shorts or swimming or running . . . or when my clothes can’t even brush against my skin.” By mid-week I was walking around holding my hip, which made the discomfort bearable. I could also be heard exhaling deeply from time to time to take my mind off the pain.

“But just on one side?”

“Yes,” I said. “That lasted all week, so it wasn’t just a run of the mill irritation. Then on Friday I noticed that I had a very swollen lymph node on the same side. At first I could feel it, but now I can actually see it, too.”

My doctor was starting to look like he knew what was wrong with me. What I didn’t say was that, after I found the lymph node, it was too late to get into the doctor’s office on Friday, and I kinda had a little freak out over the weekend. What was wrong with me? I didn’t have most of the symptoms of the few things I could think of. If it was a hernia, would my season be over before it started? What if it was more serious than that?

“And then I noticed a cluster of bumps on my back. They don’t really hurt, but they started around the same time. Now I have a few on the front of my thigh, too.”

“You have shingles. You’re the fifth person in the last week that I’ve seen with it. That’s really unusual.” And then he pointed to the poster from the CDC behind him on the door. It was the poster I had started to look at before he came into the exam room. On it, sad-looking, line-drawn people had shaded swaths on one side of their bodies. Then he gave me a prescription for the drug you get if you have herpes.

I was starting to feel much better a few days after starting to take the valaciclovir. I still feel a little pain just below the skin in my hip, and I’ve read that the neuralgia—which is what this kind of nerve pain is called—can last months. Yet I still feel fortunate that my shingles wasn’t as bad as some of the pictures I’ve seen or stories I’d heard.


BG Crash: Meanwhile, I was still swimming, cycling, and running. Swimming was going well, and I felt like I was getting back to my pre-illness form and speed. Running was . . . amazing! I’m still not super speedy or anything, but I noticed that at some point over the interminable winter my form improved, and as a consequence I seem to be able to run faster with the same amount of effort. Cycling is another story, since I found myself a bit off my form the end of last season. What I needed was time in the saddle. So about a month ago, I switched from mostly running to mostly cycling. I want to say that it’s been slow, but really I’m progressing pretty quickly, getting in a couple of 60-mile rides over the last two weekends. Hopefully, I’ll be speedy on Sunday for the first tri of the season and ready for the 100-mile Tour de Cure gran fondo next weekend.

One thing that has been completely different—and very frustrating!—compared to last year is my diabetes abilities in the afternoon. Almost every workout for a couple of weeks ended with me either 100+ mg/dL (5.5+ mmol/L) lower than where I started. That’s quite a drop, especially given that I had been working hard to keep my BGs in a “better” range. As a result, I was having a bunch of lows (or near misses) while exercising. No amount of pre-emptive eating seemed to fix anything. The worst was a span of three days where I had to stop cycling and running in order to treat hypos. I hate stopping.

It occurred to me that a few things were different. As I already mentioned, my BGs are bit better throughout the day, which (unfortunately) gives me less room for a drop like this. My training volume is also higher now, which means I’m more likely to use blood sugar, since my muscle glycogen might be slightly lower. And—this probably is the key—I had ever-so-slightly more active insulin in my system than last year. I remember being hungry in the afternoon everyday last summer and not eating because it would mess up my afternoon running or riding. Surely, there’s got to be a better way to balance the need to eat and the need to exercise. I should go back to my TeamWILD notes from last year to remember how much to lower a bolus for food depending on how far in advance of riding it is. Stay tuned.


An Actual Crash: Last Sunday, I went out for a little ride. It was a beautiful day; Chrissie (my tri-bike) and I hadn’t been out for a long ride together for a while; and I was feeling pretty energetic. About 20 miles in, I decided to stop at the same park I did the weekend before to take a little “nature break.” The previous time, I accidentally punched myself in the face taking off my arm-warmers. This time I didn’t even make it into the park before starting the mayhem.

Turning the corner from the highway to the park at about 10 MPH, my wheels hit sand, and I slid to a stop on my right side. Two women walking down the street saw the crash and asked if I was okay. As I stood up, nothing felt broken, although I could already feel some pain on my right leg despite the adrenaline. I’m fine. The ladies seemed dubious. So I looked at my bike and saw everything was (thankfully) exactly as it was supposed to be. My insulin pump seemed unharmed. And then I looked at my knee and shin. Blood and scrapes, but nothing that wouldn’t heal or keep me from finishing the next 40 miles. Yes, I’m okay. Thanks. All things considered, I wasn’t badly hurt—just a little road rash—although I was bleeding pretty well.

I headed into the park to do what I’d gone there to do, and then I spent a few minutes cleaning out my wounds. The bleeding from my knee wouldn’t really stop in the 30 seconds that I was willing to give it, so I used my beanie (which I no longer needed on this ride) to blot the blood and headed back out. I think I scared a few people I saw on the remainder of my loop. When I got home, Lisa didn’t believe me that it was a wolverine attack, so I had to fess up that the blood was, in fact, my own and convince her that I was, in fact, okay. After a shower it looked much better. Now, about a week later, the scabs look a bit gruesome, but the injuries they cover feel fine.


It’s been the strangest two months since the New Bedford Half Marathon, and hopefully nothing else happens between now and Sunday.

Posted in Cycling, Diabetes, Life Lessons, Reluctant Triathlete | 3 Comments

Let Me See Them Hands

Posted on May 6, 2013 by Jeff Mather

I noticed a trend recently of hands showing up in my photographs from museums. Here are some of my favorites. Do you recognize any of these hands? (Click on any image to enlarge it. You can also start at the first and click your way through.)

Posted in Crusty Old Paint, Photography | 1 Comment

Patient-centered Care Works Better

Posted on May 1, 2013 by Jeff Mather

Here’s some shocking news, as reported in the Reuters article “Patient-centered care linked to better outcomes.”

Patients tend to do better when their doctors pay attention to their individual needs and circumstances, according to a new study.

“In a sense that sounds sort of obvious, but no one has ever showed that before,” said Dr. Saul Weiner, the study’s lead researcher.


Updated 6 May 2013: Lisa asked, “Why is this research necessary? I mean, it’s obvious isn’t it?” To which I responded, “Without the research, doctors can dismiss intuition and keep doing whatever it is they do now.”

Posted in Diabetes, Health Care | 1 Comment

7.3

Posted on May 1, 2013 by Jeff Mather

When I was at my general practitioner’s office on Monday getting diagnosed with a case of shingles—more about that another time—I asked if I could get my A1c drawn in anticipation of my endo appointment on Thursday. My GP and endocrinologist are in the same health network, so they both use the same electronic health record (EHR) system, and it would save me a trip to the hospital lab before work. “No problem. We’ll check your electrolytes and whatnot while we’re at it.”

Whenever I don’t expect good things from my A1c, I’m often pleasantly surprised. After a few months that included being ill, traveling, and having some bat-shit crazy BG readings, I was expecting something closer to 7.7 (where I was in January) or even 8.0.

Fast-forward one day to yesterday when I checked my EHR and saw my spiffy new A1c of 7.3. I know we “strive for 6.5,” but I was really happy to see the lowest A1c in the last six years.

Posted in Diabetes | 3 Comments

Mo Pixels, Mo Problems

Posted on April 29, 2013 by Jeff Mather

Technology might be making the world a smaller place, but the data we’re creating and using is only getting bigger and bigger. Recently a few customers independently contacted me with problems reading their large DICOM (medical) and NITF (national intelligence) image files. I learned a lot about importing and exporting files larger than 2GB in size. It turns out, simply using size_t in C++ for the type containing file positions isn’t enough, and the solutions are not completely portable between different architectures. (MATLAB currently supports three different architectures and compilers that can handle 64-bit addressing: Mac OS, Linux, and Windows.)

Because of the sensitive nature of the work done by the community that uses NITF files, I was 99% certain that it would be impossible to get a file that reproduced the problem. Nor would I be able to get a metadata dump that showed all of the important things: image and tile dimensions, bit depth, expected offsets in the file to important data, exact file sizes, etc. Fortunately, the customer was able to tell me approximately how big the files were when the problem did and didn’t occur; he also shared the data type and the fact there were two images in the file. After several days of tearing apart reverse-engineering a couple of publicly-available-but-hard-to-find, declassified sample files from the National Geospatial-Intelligence Agency. I was able to create a 16 gigabyte file containing a bunch of grayscale ramps that reproduced the behavior the customer reported. Whew.

Here’s an example of what each of these grayscale ramps was supposed to look like:


Imagine that each of these tiles is 4000×4000 pixels and that the file has 125 of them. That’s a lot of pixels.

It turns out that because of a perfect storm of misunderstanding 64-bit file I/O, the file reader (1) opened the file in a mode that didn’t necessarily support 64-bit addresses, (2) used a data type that couldn’t necessarily map large addresses to their exact location in the file, and (3) occasionally started reading in the middle of a 32-bit floating point value instead of the beginning. You can understand why the data would be corrupted. What I hadn’t expected was how trippy the data would look. Here is an example of what happens when the location where I/O starts in the wrong place and slices into a single-precision floating-point value in the middle of a word:


Zooming in a little is even cooler. Open the image to see it in all of it’s groovy glory.


Hopefully, even if you were thinking, “Oh my g-d, Jeff Mather, you are such a geek!” you at least thought the pictures were cool. Welcome to the sexier part of my 9-5 7-4 life.

And just to reiterate, no national security secrets were learned or shared in the creation of this post. All of the data is synthetic. I’m only adding this disclaimer because someone at the office was worried that some enterprising spy agency could somehow get our secrets from the jumbled pictures. “Too many secrets . . .”

Posted in Computing, File Formats, Fodder for Techno-weenies | 1 Comment

Back to the Pool: A Story in Four Acts

Posted on April 22, 2013 by Jeff Mather

I. Between being sick and the high school being closed for spring break, today was my first day back at the pool since the 10th. I had gotten a little used to sleeping in—all the way to 5:30—but I was still pretty happy about the chance to get my swim on. How would it feel? Pokey? Speedy? I had no idea. Frankly, I didn’t care; I was just happy to be back. Usually I have a plan, and today I decided to swim 2,000 yards continuously. Easy to remember.


II. I was glad to see Pat there when I arrived.

“How was your marathon?” I asked, and she made a face that was hard to decipher.

“I ran twenty-five and a half miles. I was feeling really good. It was so weird; we were all running, and then we literally all just stopped inches away from the person ahead.”

“Man, that sucks.”

“Yeah, but I still have my legs, so I can’t complain. I’m just glad my daughter met me at the 20th mile to run with me a bit, instead of waiting at the finish line.” I did the math on the way into work. At the pace she was going and the distance she had already run, she was probably less than five minutes away from the finish line when the bombs went off.


III. I have a little ritual I do three times a week at the pool. I sign in at the little table on the pool deck and then walk to the nearest open lane, where I sit and dangle my legs over the edge while I put on my swim cap and adjust my goggles. Then I look down at my watch and reset it before hopping into the water and convince myself to get going. Today, when I went to look at my watch, all I saw was the fur on my arm.

Oh dear, this could be a problem. How would I know how far I had gone? For a continuous swim, my pace is slow enough that I can pretty easily use the time on my watch to figure out my distance. “A little under 33 minutes swam,” I can say to myself, “means 33 laps. Only seven more to go.” No watch means no easy lap-counting.

Pat offered to lend me her watch, which I’m pretty sure is a water-resistant analog watch with a leather band. Not that there’s anything wrong with wearing a lady’s watch in the pool, but it’s an interesting sartorial choice. (Of course, Pat did wear sunglasses at the reservoir for a couple weeks before somebody suggested goggles with optically corrected lenses. And I’m glad they did, because I got in on that action really fast. Seeing where you’re going is a good thing.) I declined the watch offer, since I thought it would be nice to have a little bit of extra freedom, and the wall clock would tell me how long I took to do my 2,000 yards. I started at 5:45, almost on the dot.

Without a watch I had to pay attention to swim the right amount. I counted . . . en español on the way out and en français on the way back. Uno/un to bente/vingt twice. That seemed to work pretty well. Having a lane to myself also helped, since there were fewer distractions: I didn’t have to worry about anyone getting in my way, and the lane dividers made it harder to see what was going on in neighboring lanes.


IV. At the end of my swim, the guy one lane over (who was recovering between sets) asked, “Do you do triathlon?” Yes. Yes, I do. So we chatted a little bit about how much fun it is. He told me that he will be doing the same tri in Hopkinton that I will. “I guess the water is only supposed to be 60º.” I didn’t have the heart to tell him that last year it was around 56ºF (13ºC). “Do you do a warmup swim?” Personally, no, but I never do a warmup. (It’s just another variable with with the pre-event diabetes management. Plus, that’s what the first couple minutes of the race is for, right?) “I’m just worried I’ll get out and be cold while standing around for the start.” Yeah, that’s a real possibility (and another good reason not to do a warmup), but the water will definitely take your breath away.

Only three more weeks. I can hardly wait!

Posted in Reluctant Triathlete, Swimming, This is who we are | 1 Comment