In this time we’ve had lots of regular readers, one-time visitors, and excellent feedback. By comments, our most popular post continues to be our MATLAB Mobile introduction, followed distantly by our post on MATLAB on Snow Leopard. Keyboard shortcuts and UITABLE have also been very active topics over the years.

Those of you are who are regular readers may have noticed that the distribution of community posts to strictly desktop posts has been changing over the past two years, and now we’re making it official. I am handing this blog off to the MATLAB Central team, so welcome to the MATLAB Spoken Here blog. We’ll still have desktop topics from time to time as they come up, but the regular focus will be the File Exchange, Cody, Trendy, Answers, the MATLAB Contest, MATLAB Mobile, and other exciting new web and mobile products as they come online.

Thank you for your readership and support, and keep coming here week after week to find continued success using MATLAB in all its forms.

From there, MATLAB will connect to the internet and scan your computer to determine what updates are available for your installed products.

If you’re ready to upgrade, just click the “Download Products at MathWorks.com”, and you’ll be brought to our website with instructions on how to get those products onto your hard drive.

Voila! you’re ready to go with our latest features. Be sure to check this out in the fall to get all the awesome things coming with MATLAB R2012b.

• Enhanced graphics and styling
• Consistent iPhone and iPad UI
• Rich command history
• Hotlinks in error message suggestions

I’ll let the snapshots do the talking.

Larger, Sharper Keyboard Graphics

           MATLAB Mobile 3.1                                                                                     MATLAB Mobile 3.2     

Command-Result Distinction

           MATLAB Mobile 3.1                                                                                   MATLAB Mobile 3.2     

Enhanced Command History

           MATLAB Mobile 3.1                                                                                  MATLAB Mobile 3.2    

Download MATLAB Mobile 3.2 from the App Store and do let us know what you think.

The 11b Embedded MATLAB Editor

The 12a MATLAB Editor with an Embedded MATLAB block

If you’re interested in Embedded MATLAB and other Simulink topics, be sure to subscribe to our Guy and Seth on Simulink blog.

Using Cody to solve a problem like this has numerous advantages. First off, you’ll get an answer quicker and more complete than you would by asking me to help you out. Second, it will only cost your time. Third, it helps out the Cody community by keeping the pipeline full of interesting challenges.

Creating a new problem is simple and fun:

1. From Cody, press the big blue “Create a Problem” button.
   
2. Fill out the problem title and description. If you can formulate the problem clearly in a few sentences, it’s a big indicator you’ll get your problem solved.
   
3. Finally, you need to create a test suite to make sure the problem gets solved. The more robust the test suite, the better the solutions will be. Be sure to cover cases like empty value, repeat values, out of bounds values, etc.
4. You can create an optional reference solution. Reference solutions are good if you’re providing a brain teaser that you’ve already solved. But if this is a problem you don’t know yet how to solve, feel free to leave it out.
5. Publish it.
6. Profit!

Try out the problem I created for Mark and try to beat my answer!

Just remember that Cody rates problems based on an approximation of code size, which may not be the best code for maintainable, reusable project.

In MATLAB Mobile 3.1 on both iPhone and iPad, we’ve incorporated this behavior for each of the symbol keys in our custom keyboard rows. We’ve grouped symbols together in a way we think are logical: brackets, quotes, punctuation, math operations, logical operations.

Here is a catalog for the iPhone:

The iPad has the same set of keys in addition to the digits 0-9. The digit keys do not have any extra keys behind the tap & hold.

Let us know what you’d like to see in the next iterations of the keyboard, in the comments below.

What’s new? Here’s the short list.

• Notifications
• A Solutions page
• A Comments page

If you like Cody, you’ll definitely want to turn on notifications for new problems. Here’s how you do it. Go to your “My Cody” page. At the top right you’ll see a link for My Cody Preferences. Once there you can check boxes so that you will be notified in any of the following situations:

• New problem
• Comment on a problem that you created
• Comment on a solution to a problem that you created
• Comment on a solution that you submitted

In addition to notifications, we now have a master solution page and solution search capabilities. From the navigation panel on the left side of the main page, select “Solutions”. From this page you can do interesting searches like: how many solutions use the function bsxfun? Of course, you won’t be able to read through the actual code until you’ve unlocked the answers for the corresponding problem. But as you solve more problems, this search tool becomes an ever more valuable resource. By the way, there are currently 750 solutions that use bsxfun. What is bsxfun? I’m glad you asked. That’s just the kind of thing that Cody is good at. You see all the cool kids using a function you’ve never heard of and you realize that’s it’s time you went and read the documentation.

Along with the solutions page, there’s also an aggregated comments page. I like being able to see what people are talking about, whether it’s an especially interesting solution or a problem that could use an improved test suite.

Finally, as promised, I want to go back to a feature that’s been in Cody since the beginning: the Solution Map. Recall that the Solution Map plots solutions as points against two axes: order of arrival (horizontally) and code size (vertically). Correct answers are green circles. Incorrect answers are red x’s. Cody is a window into how people write code and the Solution Map reveals some interesting patterns.

Some of the patterns are obvious. In a simple problem like Is My Wife Right? we see a rail of solid green. There is a single obvious answer (‘yes’. Duh), and anyone who doesn’t use it is just goofing around.

Some problems, say Triangle Numbers (problem 5), have two rails. There are two straightforward answers, and they really pop out at you in this view.

As the problems get more complicated, there is much more variety in the solution space. Here is the Perfect Squares problem (problem 23).

But within this chaos we find dozens of little dramas, each telling the story of some far-flung soul grappling with ferocious NaNs, sinister array indices, and the beguiling mysteries of the find command. You find small patterns of rising and falling action. In rising action, we observe a pattern of repeated failure as the code gets bigger. Once success has been achieved, we might see falling action: repeated successes as the code gets smaller. Here’s an example. Watch as Cody (and Contest) superstar Alfonso Nieto-Castanon steadily improves his code for problem 317, Find the Stride of the Longest Skip Sequence.

Here’s the link: http://www.mathworks.com/matlabcentral/cody/problems/317/solutions/map?term=player%3Aalfonso

Did you notice the solution search functionality in the Solution Map there? We’re doing a search for Alfonso’s code only. Once on this page, you can use the left and right arrows to page through the solutions.

Want to see all the answers to Problem 497 that use the hankel function? Try this search.

http://www.mathworks.com/matlabcentral/cody/problems/497/solutions/map?term=hankel

Cruise around the solution maps of Cody. Use the search. What dramas do you see?

To transpose or sort variables, use the right-click menu options in the Variable Editor. You can sort variables based on single or multiple column selections. The columns you select can be non-contiguous and should always include all the rows. Also, you can create variables from non-contiguous data selections.

See the New Variable Editor Features in Release 2012a video for an in-depth overview.

One particular pick I want to call out is: “Publish dependent and called functions”, a submission that publishes a MATLAB script/function along with its called functions. You just need to provide the top level file to publishdepfun, and it will publish that file along with any user-defined functions used from that file. The called functions’ publish outputs are appended to bottom of the main output file, so you have them all in one handy document.

Try it out, and subscribe to the Pick of the Week RSS feed to stay in tune with what’s going on there.

Since I’m a MATLAB programmer, I wrote some MATLAB code to pull the number off the web page and store it in a MAT-file. I kicked off MATLAB every night with a scheduled task on my PC, and it would gather and plot the necessary data. This worked well enough, and soon other people were asking me to track things: sales numbers, file sizes, bug counts, headcount numbers. These data sources are all similar in two important respects: they’re slow-moving trends (gathering data once a day is fast enough), and the information is available on a web page somewhere. At that point I realized we had an opportunity to make a simpler and more general service: Trendy.

Trendy is a web service that makes it easy for you to track and plot slow-moving trends. You only need to give us two little chunks of MATLAB code: one to collect the latest data point for a trend you care about, and one to plot the resulting trend. We take care of the rest. We’ll store your data in a safe place and we’ll remember to run your code every night.

Here, for example, is the data I’ve been collecting on the number of files on the File Exchange. It’s hard to make sense of a list of numbers without plotting it. So here is a plot of the same data.
Notice that separating the trend’s data from its plot has some benefits. For one thing, I can do multiple plots of the same data. I might want to plot the rate at which files are coming in (with data smoothing). Or I might want to use linear extrapolation to predict how long until we hit a certain threshold.

Because everything on Trendy is public, you’re welcome to plot someone else’s data. Teja Muppirala made a cool plot of the number of sushi and ramen restaurants in Tokyo. When I saw Teja’s plot, it occurred to me to plot the ramen-to-sushi index. Noodles are cheaper than fish, so who knows? Maybe this can be used as a leading indicator for the Japanese economy.

Trendy is designed to remove the tedium of data collection, but as a side effect it also give you something else: data transparency. If you see an interesting plot, you can say “Show me the data.” And if you’re still curious, you can say “How did you get that data?” The data source is just a click away.

When you first create a trend, it seems maddeningly slow to fill up with data. But then you forget about it for a few days, and the next then you know, it’s revealing some fascinating patterns. Like the time-lapse movie of a sprouting bean, when you put on your slow eyes, you see things you never noticed before. We’re used to living in a data-rich world. Numbers are good. But for every number you hold in your hand, Edward Tufte is asking “compared to what?” From Premier League football to the solar system and beyond, Trendy helps you make sense of the numbers you care about.

Try it!