Repeated Indexing in MATLAB

Indexing is a popular topic I write about from time to time. Today I want to focus on what happens when there are duplicate indices....

標簽: Indexing

Loren on the Art of MATLAB

2020-01-31 16:30:59

Racing bar charts

Jiro's Pick this week is barChartRace by Eiji Konaka.This an example of a nice outcome that spawned from a community discussion. It all started with this tweet. Translation: "Is there a simple MATLAB function that could easily create this animation? I want it..."I learned that this type of animation, where the bars switch places based on the order, is called...

標簽: Picks

File Exchange Pick of the Week

2020-01-31 10:39:46

Activity Classification Demo

Every January, our company hosts an annual “kickoff”: an opportunity for sales, marketing and folks in customer facing roles to meet in Boston and learn about all the new and exciting features coming in 2020 for their relevant product areas. Being on the deep learning marketing team, we decided to put words into actions by providing everyone the opportunity to...

標簽: Uncategorized

Deep Learning

2020-01-30 19:57:48

Moving Graphical Script Code to App Designer More Debugging

I need to continue debugging the code that I moved into App Designer by updating all plotting functions to specify a specific axes. I forgot I defined a bunch of interactivity callbacks (mouse-over, click and scroll wheel etc). Features covered in this code-along style video include: Specifying target axes with plotting commands ButtonDownFcn, WindowButtonDownFcn and WindowScrollWheelFcn properties and...

標簽: App Designer, Code-Along, Format: Video

Stuart’s MATLAB Videos

2020-01-30 13:49:36

Pejorative Manifolds of Polynomials and Matrices, part 2

In an unpublished 1972 technical report "Conserving confluence curbs ill-condition," Velvel Kahan coined the descriptive term pejorative manifold. In case you don't use it in everyday conversation, pejorative means "expressing contempt or disapproval."Velvel's report concerns polynomials with multiple roots, which are usually regarded with contempt because they are so badly conditioned. But Velvel's key observation is that although multiple roots are sensitive to arbitrary perturbation, they are insensitive to perturbations that preserve multiplicity.Part 1 was about polynomials. This part is about matrix eigenvalues....

標簽: Calculus, Eigenvalues, Numerical Analysis, Precision, Symbolic

Cleve’s Corner: Cleve Moler on Mathematics and Computing

2020-01-30 11:58:29

Pejorative Manifolds of Polynomials and Matrices, part 1

In an unpublished 1972 technical report "Conserving confluence curbs ill-condition," Velvel Kahan coined the descriptive term pejorative manifold. In case you don't use it in everyday conversation, pejorative means "expressing contempt or disapproval."Velvel's report concerns polynomials with multiple roots, which are usually regarded with contempt because they are so badly conditioned. But Velvel's key observation is that although multiple roots are sensitive to arbitrary perturbation, they are insensitive to perburbations that preserve multiplicity. The same observation can be applied to matrix inverses and eigenvalues....

標簽: Calculus, Numerical Analysis, Precision, Symbolic

Cleve’s Corner: Cleve Moler on Mathematics and Computing

2020-01-18 10:40:50

MATLAB Benchmark Code for WiDS Datathon 2020

Introduction Hello all, I am Neha Goel, Technical Lead for AI/Data Science competitions on the MathWorks Student Competition team. MathWorks is excited to support WiDS Datathon 2020 by providing complimentary MATLAB Licenses, tutorials, and getting started resources to each participant. To request your complimentary license, go to the MathWorks site, click the “Request Software” button, and fill out the...

標簽: Data Science, Live script, MATLAB

Racing Lounge

2020-01-17 20:52:10

A New First Order Hold!

If you are attentive to details, you might have noticed that in MATLAB R2019b, we removed the First-Order Hold block from the Discrete section of the Simulink Library browser. At the same time, we added in the Continuous section of the Simulink Library a new First Order Hold block. Why a new First Order Hold? One of the questions...

標簽: Performance, Simulink Tips, What's new?

Guy on Simulink

2020-01-17 10:45:58

digCircs

Sean's pick this week is digcircs by Graham W Griffiths. My pick this week is a really cool visualization of the numbers in a sequence. digCircs draws colored parabolic lines between sequential digits in a sequence. Take a look at the first 10000 digits of pi: or e: Now there's actually another reason I picked this. A...

標簽: Cool feature, Picks

File Exchange Pick of the Week

2020-01-17 09:00:56

Treble clefs, Unicode, SVG, strings, Bézier curves, kron, implicit expansion, and polyshape

Today I will show you how I plotted this treble clef symbol in MATLAB: My discovery and implementation process for doing this involved Unicode characters, SVG files, string processing, Bezier curves, kron, implicit expansion, and polyshape. I thought it was fun, and I learned a few things, so I wanted to share it.As a personal project, I make specialized fingering...

標簽: Uncategorized

Steve on Image Processing and MATLAB

2020-01-16 17:39:22

Computer vision algorithm removes the water from underwater images

Underwater photography is hard to get right. Special filters, artificial lights, and top-of-the-line underwater cameras can help, but there’s still a lot of water between the camera and the object in the photo. We’ve become accustomed to the blue-green tint of underwater photography. Before: A coral reef in the Red Sea, Israel. Image Credit Matan Yuval, Marine Imaging Lab,...

標簽: Uncategorized

Behind the Headlines

2020-01-16 17:30:02

Moving Graphical Script Code to App Designer

I've been developing a script for a while to display the structure of part of our website. It involves plotting a graph and manipulating it and the axes. Now I want to move this code into an app because eventually I want to deploy it as a web app. Here, I go through the process, including converting the code to...

標簽: App Designer, Code-Along

Stuart’s MATLAB Videos

2020-01-16 12:35:17

Rayner, BAE Systems, and Cody

This week we're very fortunate to speak with Rayner Saggers. Rayner is a Senior Systems Engineer on the F-35 Program at BAE Systems in the UK. That's already pretty cool, but in addition to that, he's a pillar of the MATLAB community at BAE Systems. He is the editor of the BAE MathWorks User Group newsletter, and he manages the...

標簽: Uncategorized

MATLAB Community

2020-01-14 18:05:52

How to Chart My Year

I travel a lot. Mostly for work. I do try to take advantage of the priviledge - visiting so many amazing places -- and spend a little extra time occasionally. People even joke that I should be writing a travel blog. Of course I prefer to write one on MATLAB. But how about combining these just for fun today.Another observation: I find that often people don't include enough information on their plots, from axes labels to good titles. And sometimes the story we want to tell is complex. Including how we present the data. Good labels and titles go a long way to remedying the situation.You may have noticed some recent posts about a new feature in MATLAB: tiledlayout, meant to supplant subplot. Here are Steve's post and Sean's on POTW.I thought it would be fun to make a "calendar" of sorts for my travels. As the year goes on, I hope to replace the plot each month with an iconic picture from my travels. I will start it off with junk data. And I want to show my meanders a bit as well. For now, again, the plot will be with nonsense data, to be filled in as the year goes on....

標簽: Uncategorized

Loren on the Art of MATLAB

2020-01-14 14:34:48

Determining next available file name

Jiro's Pick this week is nextname by Stephen Cobeldick.Stephen is no stranger in the MATLAB user community arena. As of the writing of this post, Stephen ranks 44 out of over 15,000 File Exchange users. He also ranks 5 out of over 190,000 MATLAB Answers users. One of his files have been Picked not once, not twice, but three times...

標簽: Picks

File Exchange Pick of the Week

2020-01-10 11:18:07

Send Email Alerts from ThingSpeak

For this post, I would like to introduce Christopher Stapels as our guest blogger. Christopher builds lots of cool IoT projects and is omnipresent on MATLAB Central and ThingSpeak and MATLAB questions. He is also the product marketing manager for ThingSpeak and MATLAB hardware here at MathWorks. Welcome to the team! ThingSpeak has added an alerts API to let...

標簽: News

Hans on IoT

2020-01-10 09:59:06

Locating a 2,000-year-old Roman Shipwreck with Image Processing and AI

Archaeologists recently discovered a Roman shipwreck in the eastern Mediterranean. The ship and its cargo are both in good condition, despite being 2,000 years old. The wreck, named the Fiskardo after the nearby Roman Empire port of the same name, is the largest shipwreck found in the region to date. The Fiskardo is filled with amphorae — large terracotta pots...

標簽: Uncategorized

Behind the Headlines

2020-01-06 13:53:58

MathWorks Blue Meets Air Force Academy Blue

I have always been fascinated by the names that are used to describe colors. There are dozens of web sites with lists of color names. I was surprised to discover that the shade of blue we use in MathWorks logo is almost the same as the one used by the United States Air Force Academy....

標簽: Color, Fun, People

Cleve’s Corner: Cleve Moler on Mathematics and Computing

2020-01-01 19:55:08

Top “Behind the Headlines” Posts of the Decade

Behind the Headlines?was launched mid-decade to?focus on highlighting the role of MATLAB and Simulink in today’s most visible news stories, and the scientists and engineers that made them happen.?As we enter 2020, it’s natural to reflect on some of the top news stories of the decade. Many were devastating, from the Zika epidemic in 2016, to the rash of California...

標簽: Uncategorized

Behind the Headlines

2020-01-01 13:12:04

2019 in Review

It's that time of year again; 2019 is coming to a close as are the two thousand teens.? During the past decade, I started at MathWorks, Brett stepped down from full time posting to quarterly (thanks for your continued contributions Brett!) and Jiro moved from our headquarters in Massachusetts to the Japan office.? Will and Greg have been posting quarterly,...

標簽: Index, Picks

File Exchange Pick of the Week

2019-12-30 13:22:36

Christmas Greetings 2019

Inspired by Patsy and https://www.amazon.com/gp/product/B075JDVR53. type xmas_2019.m function xmas_2019 % Christmas greetings. set(gcf,'pos',) clf axis() axis off for k = 1:3 = base(k); patch(x,y,gray) = edge(k); flame(k) = patch(x,y,'w'); end gif_frame('html/xmas_2019.gif') for k = 1:50 r = randi(2,1,3)-1; j = randi(3,1,1); if norm(r) 0 flame(j).FaceColor = r; gif_frame end end gif_frame('reset') close function = base(k) xo = [.33...

標簽: Color, Fun, Graphics

Cleve’s Corner: Cleve Moler on Mathematics and Computing

2019-12-24 09:20:35

App for calculus students (one-variable plotting)

Jiro's Pick this week is ez plotter by Martin C.For my work, I spend a lot of my time thinking about how MATLAB can help with the learning and understanding of mathematical concepts. Being able to try things out themselves and immediately see the effect of the change is an important aspect of active learning.By its nature, MATLAB gives you...

標簽: Picks

File Exchange Pick of the Week

2019-12-20 22:45:18

Looking back on 2019

Happy Holidays, and Happy (almost) New Year! This time of year, I like to look back and remember the things we accomplished in a year. I'll recap the main themes of the deep learning blog this year, and ask you what you'd like to see in 2020. A shout out to my style transfer blog post. Theme 1:...

標簽: Uncategorized

Deep Learning

2019-12-20 16:10:15

How to Write Animated PNG (APNG) Files from MATLAB

Today, I'm writing about how to create animated PNG (APNG) files, such as this one: I first wrote about APNG files last February. An APNG file is a valid PNG image file that uses file metadata in a clever way to compress and store the frames of a full animation. See the 07-Feb-2019 post for more details about this.Just recently,...

標簽: Uncategorized

Steve on Image Processing and MATLAB

2019-12-20 12:12:25

Walking Robot Modeling and Simulation

In this post, I will discuss robot modeling and simulation with Simulink?, Simscape?, and Simscape Multibody?. To put things in context, I will walk you through a walking robot example (get it?)....

標簽: Robotics, Simscape, Simulink, Video, Workflow

Racing Lounge

2019-12-20 07:30:34

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