MATLAB Programming Contest BlogApril 21st, 2011Nick Crushes ItNear the end, everybody has the same idea. It’s obvious, really. Hold back a trick or two and throw it into the mix in the last few minutes. Then cross your fingers and hope that your number comes up. Ideas are cheap, but who can deliver the goods? I’ll tell you who, ladies and gentlemen. Mr. Nicholas Howe of Smith College, that’s who. I think I can, without hyperbole, say that I have never seen anyone so thoroughly dominate the closing minutes of a contest. Look at this scoring cliff.
Amitabh’s Sneaker was on top for a surprisingly long time, given the closing onslaught. I thought maybe that tough old Sneaker might go the distance. It was a timing game: no one was resetting the result of 6877358, but the race was on to shave seconds from the clock. And then along came Nick, with one fist of iron and one fist of steel, smashing the score lower with each blow. When the dust settled, Rapid Weight Loss May Be Harmful was high atop a list of 2713 ranked entries. Well done Nick. We send our congratulations to you (and your wife). And well done everyone! Thanks for joining in the fun and making this contest such a pleasant experience. It’s a lot of fun for us at MathWorks to watch the pros go to work. We are amazed by the display of skill. As always, now is a good time to reflect on how the contest. What did you like, and what would make it run better? How can we get more people to play? How can we get more people to watch? Some of these questions are already being discussed on the newsgroup. Join in the conversation there or leave a comment here. 
April 20th, 2011It’s official: Alan Isn’t BogusAlan Chalker, no stranger to the Contest Hall of Fame, wins our No Bogus Words mini-contest. His NBW endgame trio numbers 2, 3, and 4 topped the list at 21:00, and David Hruska, our master code wrangler on the contest team, has verified the non-bogosity of the answers. It was an exciting finish… I thought for a moment that Sergey was going to claim another prize. And there were fine last-minute efforts from Victoria, Amitabh, Andreas Bonelli, Oli, and Jin. As Alan observes in the comments, he may have been destined to win, since he suggested the No Bogus Words challenge. Alan, you should suggest more mini-contests in the future! Congratulations on this latest victory. Albert, who had a higher scoring NBW entry that came in just six minutes too late, deserves a prize for the most heartbreaking title: NBW just realized there was a deadline …. Ouch! We feel your pain, Albert. That’s a hard way to go. Albert’s entry was an interesting outlier in that it took almost 6 times longer than Alan’s winner but compensated with a substantially better result. The queue is quiet, and yet I see the end of the contest is a short hour away. This is the calm before the storm. Algorithmic ammunition, long held in reserve, is being readied for the final battle. This is our first darkened queue endgame, which should significantly change the dynamics. Soon the event horizon for inspecting competitive code will close. Then the floodgates will open and dozens of innovations will do battle for ultimate supremacy. Good luck everyone!
April 19th, 2011Ned’s Contest AnalysisNed’s been thinking a lot about this season’s Crossword Contest. You can read about what he’s been thinking by reading his Contest Analysis. Enjoy! Crossword Contest CommentaryHere are some snapshots from the latest contest. ContentsDarkness WinnerLet’s start with Alfonso’s Darkness winner, tryagain01. We’ll run it against problem 41 of the test suite. It produces this picture.
Bogus!Right away we notice that the output is mostly red. This reflects the fact that solvers are rewarded for packing in lots of short words as long as they create a smaller number of long crossing words. In retrospect, we made the bogus word penalty too low, since the result is aesthetically a little unappealing. But the rules are what they are, and within this framework, we see plenty of innovation. There’s nothing wrong with red if it gets you a good result. Sample WordsSince these letters are meaningless, I’m going to switch to some real words to make it easier to follow what’s going on. Let’s consider the words in the first paragraph of the rules. I realize it’s a little unfair to compare codes based on an example they never encountered in the test suite, so you can take this exposition with a grain of salt. YOU ARE THE NEW CROSSWORD PUZZLE INTERN FOR MAJOR MATH SOFTWARE NEWSPAPER THE NEW YORK MULTIPLY ALL THE NEWS THAT BITS AND INTS YOUR EDITOR HAS GIVEN YOU LIST WORDS USE THIS WEEK PUZZLE KNOWS YOU CAN POSSIBLY USE ALL THE WORDS HIS LIST GAVE EACH WORD WEIGHT AND TOLD YOU THE BEST YOU CAN YOU HAPPEN KNOW THAT GAVE THE SAME CHALLENGE ANOTHER INTERN YOU BETTER GOOD JOB YOU WANT KEEP YOUR POSITION MAYBE SOME SOFTWARE WOULD HELPFUL HERE Naturally, the character of the answer depends on the weights and the penalties. For this problem, let’s say that the weight is the length of the word. Penalty = 0For zero penalty and grid size of 15, Alfonso’s code returns this.
Penalty = 4For a penalty of 4 (the median weight of the words in our dictionary), we get this.
Penalty = 9The highest weight word is 9. When the penalty is 9, there are no more bogus words. Legal crossing words are completely absent in all three solutions.
Twilight Winner, Penalty = 0Let’s move on to Nick Howe’s Twilight winner, Star Crossed X. This is the zero penalty solution.
Yow! That’s a jam-packed grid. Here’s what happens when we boost the penalty to 9. Twilight Winner, Penalty = 9
Now there are no bogus words again, but still no usage of crossing words anywhere on the grid. No Bogus WordsThe other mini-contest winners from Saturday and Sunday that I looked at returned very similar results to those shown above. From the point of view of looking at “interesting” results, we need to skip ahead all the way to the No Bogus Words entries. For NBW entries, the penalty is effectively infinite. This is NBW Weighty matters from the cyclist. We’ve finally got some crossing words! Three, to be precise, but that’s more than none.
Scrabble ScoresSuppose instead of rewarding solvers for the length of each word, we instead rewarded them for their Scrabble scores. The longest words used to be 9. But now the highest value word is PUZZLE, with a score of 26.
The Last Example: A Recent LeaderThis is Oli’s NBW Hoola Hoop. It’s the highest ranking NBW entry as of Tuesday morning, Natick Time. We’ve still only got a couple of crossing words.
How Do the Pros Do?As a quick taste of what is possible with these same words, here is the output from a free crossword grid construction program, EclipseCrossword. Here we are fitting 30 words into the same space where the leading contest entry can only fit 20. Again, it isn’t a fair comparison, since these two programs are working on different optimization problems. But it’s fun to compare.
Published with MATLAB® 7.12 
Sergey, Master of a Thousand NodesDidn’t I tell you? Watch out for Sergey, I said. He’s the master of the Short Form, I said. And sure enough, he swooped in with seven tightly packed entries between 15:44 and 16:00 UTC, and now he’s at home counting his prize money. Or he would be if there were any prize money. Congratulations (again) to 1000 Node challenge winner Sergey Yurgenson. I have a sneaking suspicion that he’s really good at tuning up small cars, fixing watches, and maybe building sailing ships in bottles. In any event, he sure knows his way around a few hundred lines of MATLAB code. Here is his winner, CrossCat7. Nice work Sergey!
April 18th, 2011Three Mini-contestsWe’re in the final few days of the contest, and we know that you’re anxious to know what prizes remain to be claimed. We’ll give you a few options. First of all, we’re bringing back the venerable 1000-Node Challenge. The 1000-Node Prize will go to the entry with the best score that
Remember, you don’t need to shorten your variable names or remove comments to win this challenge. That’s exactly why we made it a node-count prize and not a character-count prize. This is how you calculate your node count. t = mtree(filename,'-file'); length(t.nodesize) Sergey is the acknowledged master of the Short Form. Can you beat him? Next, as suggested we’re going to try a No Bogus Words Challenge. If you want to enter, you need to signal it to us by putting the three letters NBW at the beginning of your entry’s name (e.g. “NBW My Super Duper Entry”). We’re not changing the contest scoring code, so we’ll be checking your code after the fact. When the deadline has passed, we’ll look at the leading NBW entry and check it. Beware: if it actually does use any bogus words, the author will be disqualified from winning the NBW prize on any other entries, and we’ll move on to the next potential winner. The NBW winner needs to be submitted before 21:00 UTC on 19 April. (If we had it all to do over again, we’d probably have made the bogus word penalties higher. But you never know how things are going to go until you start the contest and see what entries come in.) Finally, there’s the Six Million Dollar Man prize. If you can break 6,000,000 for your “result”, regardless of any other consideration, you win the prize (note that you don’t actually win $6,000,000). Naturally, you can’t exceed the time limit, but other that that, all that matters is the result. My friend Dave on the contest team says it can’t be done. I realize it’s a stretch goal. We’ll just throw it out there and see what happens.
Haiku WinnerIt gives me great pleasure to award the Haiku Challenge prize to Nick Howe’s wife Susannah. Her inspired poetical lament, haunting and epigrammatic, I now reproduce in its entirety: Oh no! Contest time. Here at the Global Contest Headquarters we have a special place in our hearts for the MATLAB widows and widowers out there who tolerate our twice-yearly shenanigans. So it was delightful to hear from one, in poignant verse form no less! Perhaps it is no surprise that, in the name of marital harmony, we have been asked at various times over the years to keep the contests short and infrequent. Thank you for your patience Susannah, and now you’ll have a prize of your own to put on the mantel next to Nick’s. The judges also send an Honorable Mention to Alan Chalker for his prodigious poetical outpouring, and especially his versification in MATLAB. So many choices
Weekend Winners: Amitabh and FelIf you’ve been watching the statistics over the weekend, you know the result. We’ll make it official by awarding a Saturday Leap prize to Amitabh Verma for the breakthrough entry Crazy Ivan on Kangaroo Jack. I always like entries with entertaining names, so extra marks for that and well done Amitabh! At 1.11% improvement over the previous leader, Crazy Ivan was the biggest single advance since Alfonso’s Darkness leaders. As we like to point out, it gets harder with each passing minute to make a big improvement, so congratulations to Amitabh for advancing the state of the art so dramatically. And based on his profile picture, I’m guessing he’s a mean bowler too. Double threat: bowling and MATLAB. Maybe there’s some sort of biathlon competition in there? The Sunday Push prize goes to Fel for his “Dead End Strategies” series. Notice that Fel’s best entry for the day would have won the prize all by itself. The mysterious Fel revealed himself to be David Felguera in the last contest where he also did some weekend work, winning the prestigious Sailing Home Saturday Leap prize. Now he’s got both weekend prizes for his trophy room. I think that might be a first… Congratulations to Fel for the largest aggregate improvement for all of Sunday!
April 15th, 2011Saturday Leap and Sunday PushAs has become our custom, we will be running two mini-contests this weekend. The Saturday Leap prize goes to the person who makes the single biggest percent improvement for any entry with a submit time on Saturday, 16 April. Keep in mind that our times are registered against Universal Time; the time stamp on your submission is the thing that matters. The Sunday Push prize goes to the person who makes the biggest cumulative improvement for any number of submissions received on Sunday, 17 April. Watch the statistics page for information showing who’s doing the best as the weekend progresses. We will also be awarding a prize to the author of the best MATLAB Programming Contest Haiku. Whereas most of the contest is a purely objective competition that rewards steely logic and intellectual firepower, the Haiku Challenge judging will be completely subjective and arbitrary. It’s just a fun exercise for your neglected right brain. The prize is certain to be cheap. Submit your entries in the blog comments. Have a great weekend!
Nick, How Do You Do It?The indefatigable Nick Howe has claimed yet another prize to add to his virtual shelf-full. If you visit his author page (make sure you’re on the one that corresponds to all contests), you’ll see he’s won no fewer than eight prizes of one kind or another. I won’t guarantee this is all of them, since we’ve done an imperfect job so far of matching up badges with past prizes. It’s clear from this list that Nick does his best work at night, with six of those prizes coming in either Darkness or Twilight. Nick had some good competition from James White and Victoria (not to mention Darkness winner Alfonso). But in the end, Nick’s Star Crossed X had more gas in the tank. Congratulations Nick!
April 14th, 2011Alfonso is our Prince of DarknessAlfonso Nieto-Castañón is at the top of the list for the Darkness phase of our Crossword puzzle, making him our latest Prince of Darkness. He has submitted only two entries so far (try01 and tryagain01), but these were enough to net him first and second place. Who needs quantity when you’ve got quality? His name seems familiar somehow… where have I seen it before? Ah yes! Alfonso was our Grand Prize winner for the Fall 2009 Color Bridge contest. Congratulations and welcome back to the winner’s circle Alfonso!
April 13th, 2011The Crossword Contest is Underway!The Spring 2011 MATLAB Programming contest is underway. In this season’s challenge, you are an intern at a major math software newspaper. Read Ned’s rules to find out what task the paper’s Editor has given you for this week’s paper. Better put on your thinking caps, ’cause it looks like your job may be depending on your MATLAB skills!If you are new to our contests, take a look at If this is your first contest, you might want to read the Contest FAQ or About the contest. To be truly inspired, take a look at our Hall of FameThis contest runs from now through 16:00 UTC Wednesday April 20. If you have questions or comments, you may post them here or reply to this contest’s thread in Newsreader.Good luck to everyone!Helen and the Contest team
March 15th, 2011Spring Contest Dates AnnouncedSpring is in the air and that means that the Spring contest is coming soon. It time for you to check your calendars as the contest starts Wednesday April 13th and ends the following Wednesday, April 20th. Start and end times are noon Boston time, or 16:00 UTC. If you haven’t participated in one of our contests in the past, take a look at last Fall’s Sailing Home to see how the game is played. See you all soon! Helen
November 17th, 2010A photo-finish win for AndréCongratulations to André Fioravanti for his victorious entry Lost Sailor Final5. The winner was submitted just under the wire, with only 32 seconds to spare! It was a fascinating photo finish… Sebastian Ullmann was in the lead for a long time during the tense final minutes. Many of us here thought he was going to carry away the prize, but then André’s tweak on Sebastian’s chancessss pushed him out of the winner’s circle at the last possible minute. So close, Sebastian! As it turns out, had André NOT submitted his winning entry, Rafal Kasztelanic would have won with an entry that appeared 20 seconds later! If we follow the ancestry for the winning entry, it’s remarkable that André’s winner is based on Sebastian’s, which is based on one from David Jones, which is based one from Magnus, which is based on one from the cyclist, and so on past contributions from Cameron Nowzari, Gwendolyn Fischer, Mike Russell, and previous winner Alfonso Nieto-Castanon. And of course, this is just the ancestry that the contest machinery happens to capture. Certainly the ideas of many others are expressed in the winning entry. Altogether the lead changed hands some 244 times, which I believe to be a record. And so we on the contest team offer thanks to all of you who participated and who brought your ideas to the communal table. André wins the prize, but everyone deserves congratulations.
The Queues are now closed!The magic hour has crept up on us once again and we have reached the end of this season’s contest. We have closed the contest queue. We will announce the winner once everything has processed. So stay tuned! Helen
Sergey againOur friend Sergey has another feather for his cap by claiming the 100 Node Challenge prize. His winning entry came in last night with minutes to spare. In fact, his entry would have claimed the 98 Node Challenge too, since his thrifty code didn’t even use all 100 nodes. Because it’s so short, it’s easy enough to show you the complete winning entry. Well done Sergey!
And now we are into the final minutes of the contest. Good luck everyone!
November 15th, 2010Limbo! The 100 Node ChallengeThe surprises keep on coming. I was impressed with the improvements made through Sunday, particularly noting Sergey’s big improvement with StarCat1. As I said, it’s hard to make big gains by the time Sunday rolls around, and Sergey showed us a 3.71% improvement. So I was shocked to see Peter van der Walle take the lead this morning with an incredible 4.42% improvement on his nickelfelpeter. Not only that, the size of the code started to nosedive at that point, leading us to some fierce, lean code. We often do a 1000 node challenge right about now in the contest, but since the leading entries are already at about 1000, we really wanted to set the limbo bar low. The new challenge is to see what you can do when you’re limited to only 100 nodes. Yes, that’s a tiny number, but necessity is the mother of invention. Whoever can achieve the best score by midnight on Tuesday, UTC (7 PM in the eastern US) will win the 100 Node Challenge. The top of the Statistics page has a section dedicated to showing who’s in the lead while satisfying the required 100 node limitation.
Sergey Y. is the Big Sunday PusherSergey Y.‘s remarkable entry StarCat1 would have, in one crushing blow, won either the Saturday Leap prize or the Sunday Push prize. Since he chose to submit it on Sunday, he walks away with the laurels for the Sunday Push. Congratulations Sergey for the single biggest improvement since Nick Howe’s Skookumchuck2 early on Friday. I’m a big fan of the creative naming that we see in many of the contest entries. Skookumchuck? It’s a narrow inlet in British Columbia. I had to look it up too. And speaking of trivia, here’s a question for you. The boat illustration we used for this contest has special relevance for Sergey (and the contest team). Can you identify the source of the image and why it is significant? Leave your answer in the comments here.
November 14th, 2010Leap Prize and Sunday PushIf you go to the bottom of the Statistics page, you see a colorful plot with two pink bands labeled “leap” and “push”. What do these refer to? We like to acknowledge people who make significant contributions over the weekend, so we give prizes for the Saturday Leap and the Sunday Push. We give out a Leap prize for the person who makes the greatest single biggest contribution (percent improvement) on Saturday, as measured from 00:00 UTC to 23:59 UTC. That time period is over now, and the winner is Fel, with his entry TLM – save time and invest in result, which yielded a 2.85% improvement. We’d also like to give an honorable mention to Sebastian Ullman, who made a remarkable 2.64% improvement much later in the day with splitmin1500. It only gets harder to make big improvements, so congratulations to both Fel and Sebastian for their contributions! The Sunday Push prize will be given to the person who makes the greatest cumulative contribution (based on the sum of percent improvements) to the contest. The period for this prize is midnight to midnight for the whole of Sunday, UTC. So this means it’s starting right now. If you’re the slow and steady type, now is the time to get busy!
November 13th, 2010Nick Howe once againHere’s a belated post to say that Nick did it again, claiming the Twilight Prize with his Nautilus entry. Over on the newsgroup we read that Bradley just missed winning Twilight because he had the wrong time for the start of Daylight. Bad luck Bradley, but there are more prizes to be won! Good luck to everyone this weekend.
November 11th, 2010Nick Howe is our Prince of DarknessThe polls are closed and the results are in: contest veteran Nick Howe (who has ruled the Dark more than once) is our newest Prince of Darkness. His code “Equatorial” came in at half the score of his nearest competitor. Congratulations Nick, and well done! I wanted to point out a change about timing in the rules. We listed the start and stop times for the contest as being 16:00 UTC… but we were off by one. The times are keyed to noon here in Natick, and that is in fact 17:00 UTC. Nick Howe would have won the Darkness prize with either a 16:00 UTC or a 17:00 UTC cut-off, so it had no effect today, but please note the change going forward.
November 10th, 2010The Sailing Home Contest Begins!The Fall 2010 MATLAB Programming Contest is Sailing Home and we are officially underway! See Ned’s contest rules to find out how to play. If you are a veteran of our contests, you will probably jump right to the rules. If this is your first contest, you might want to read the Contest FAQ or About the contest. To be truly inspired, take a look at our Hall of Fame to read about the winners of past contests. Post any questions or comments you may have to the Newsgroup thread. See you online! Helen
October 20th, 2010Fall 2010 Contest Date AnnouncementIt’s that time of year again! The Fall MATLAB Programming contest will be held from November 10th through November 17th.The contest launches around noon (Boston time) when we publish the contest rules. As is our tradition, we will have mini-contests with prizes throughout the contest.The contest queues will close at noon on November 17th (Boston time). Once all the submissions are scored, the Grand Prize winner will be announced. We hope that you will join us for another fun contest! Helen and the Contest Team.
May 6th, 2010Hannes Wins!In the final minutes all the secret tricks, squirreled away for the last desperate sprint, come flying into the daylight at last. We saw strong finishes from Sergey Y., Yi Cao, Abhisek Ukil, and srach. But in the end, Hannes Naudé prevailed, closing the contest with a smashing blow that knocked a whopping tenth of a percent off the score. In the past Hannes has won (together with his sometimes comrade-in-arms Cobus Potgieter) two mid-contest prizes, but this is his first Grand Prize. His hauntingly named Overfitting is a fool’s game stayed atop the grinding queue for hours, daring anyone to displace it. None could. Congratulations, Hannes, on a job well done! On the newsgroup, Hannes says some of his techniques included “intentionally overfitting the dataset, something for which I have a deep seated dislike”. I hope we can get him to write about his winning entry along with a digression on the nature of robustness and brittleness in machine learning. It’s clear that the contest is maddeningly prone to overfitting, but it’s also hard to banish overfitting from any contest or benchmark. As always, we are looking for ways to make the next contest better, and now is a good time to reflect on things we could improve about the interface and the problem. How might we encourage a richer exploration of the solution space without damaging the fun back-and-forth nature of tweak battles? Another big puzzle for us here is how to make the contest more appealing to the confused and curious crowds who watch from the sidelines. How would you turn the contest into a better spectator sport? Tell us in the newsgroup, or here in the comments, or use the User Voice page we set up for this purpose. As always, thanks to everyone for joining us, and we hope to see you next time.
May 5th, 2010Tuesday Longevity Prize Winner!News flash – Ned has just declared Alan Chalker the winner of the Tuesday Longevity Prize, with Yi Cao coming in a close second. Congratulations to Alan (and his Auto Tweeker) for winning another mini-contest!There’s about an hour left in this season’s contest. I’ve already been hearing through the grape vine that folks are fine-tuning their winning strategies for the last minute dash for the finish line. So time to go grab one more cup of coffee or energy drink and get back to that list of great ideas you wanted to try.
May 4th, 2010Mid-Contest AnalysisLast night, while many of you were coming up with new strategies for approaching this contest, Ned was busy looking at past submissions. Take a look at his thoughts in the Mid-Contest Analysis. There is a Japanese version available as well. Just one more day to go! Enjoy! Helen
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