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Exciting news for students! 🚀Simulink Student Challenge 2023 is live! Unleash your engineering skills and compete for exciting rewards. Submission deadline is December 12th, 2023!
In the past year, we've witnessed an exponential growth of ChatGPT and other Generative AI tools. AI has quickly become a transformative force across industries, from tech giants to small startups, and even community sites like ours. For instance, Stack Overflow announced its plan to leverage AI tools to draft a question or tag content; Quora built a ChatGPT bot to answer questions; and GitHub is piloting the AI tool for personalized content.
This trend in the community landscape makes me wonder what MATLAB Central community, especially in MATLAB Answers, can do to integrate AI and enhance the community.
Share with us your ideas in the comment session. Ideally one comment per idea, so that others can vote on a secific idea or have deeper discussions about it.
We launched the Discussions area with 6 channels, based on the existing types of content we see today in the MATLAB Central community.
I'm curious which channels you are most interested in participating, or which channels are missing.
Tell us your thoughts here!
Hello all,
I've been trying to shift my workflow more towards simbiology, it has a lot of very interesting features and it makes sense to try and do everything in one place if it works well..! Part of my hesitancy into this was some bad experiences handling units in the past, though this was almost certainly all out of my own ignorance, relatedly:
Getting onto my question.
In this model I have a species traveling around the body via blow flow, think a basic PBPK model. My species are picomolarities, if everything is already in concentrations, why is it necessary to initially divide by the compartment volume? i.e. 1/Pancreas below.
If my model dealt in molar quantities this would make a lot of sense, the division would represent the transition to concentrations. This, however, now necessitates my parameters be in units of liter/minute, which is actually correct, but I'd like clarification on why it's correct, ha!
Perhaps this is more of a modelling question than a simbiology question, but if there are answers I'd love to hear them. Thanks!
Adam Danz
Adam Danz
Última actividad el 13 de Oct. de 2023

Over the weekend I came across a pi approximation using durations of years and weeks (image below, Wolfram, eq. 89), accurate to 6 digits using the average Gregorian year (365.2425 days).
Here it is in MATLAB. I divided by 1 week at the end rather than multiplying by its reciprocal because you can’t divide a numeric by a duration in MATLAB (1/week).
weeks = @(n)n*days(7);
piApprox = ((years(13)-weeks(6))/years(13) + weeks(3)) / weeks(1)
% piApprox = 3.141593493469302
Here’s a breakdown
  • The first argument becomes 12.885 yrs / 13 yrs or 0.99115
  • Add three weeks: 0.99115 + 3 weeks = 21.991 days
  • The reduced fraction becomes 21.991 days / 7 days
Now it looks a lot closer to the more familiar approximation for pi 22/7 but with greater precision!
Walter Roberson
Walter Roberson
Última actividad el 28 de Dic. de 2023

This person used computer version to build a keyboard input, and used standard flag semaphore for the positions.
Flag semaphore is used mostly by sailors to be able to communicate optically over a distance; it does not need anything more than make-shift flags (but binoculars or telescopes can help.) Trained users can go faster than you might guess.
Hans Scharler
Hans Scharler
Última actividad el 27 de Jul. de 2024

Chen, Rena, and I are at a community management event. It's great to be with others talking about relationships, trust, and co-creation.
Chen Lin
Chen Lin
Última actividad el 16 de Oct. de 2023

I'm in a community conference in Boston today and see what snacks we get! The organizer said it's a coincidence, but it's definitly a good idea to have them in our MathWorks community meetings.
Walter Roberson
Walter Roberson
Última actividad el 27 de Dic. de 2023

A research team found a way to trick a number of AI systems by injecting carefully placed nonsense -- for example being able able to beat DeepMind's Go game.
This video discusses the "Cody" bridge, which is a pedestrian bridge over a canal that has been designed to move up and out of the way when ships need to travel through. The mathematics of the bridge movement are discussed and diagrammed. It is unique and educational.
Walter Roberson
Walter Roberson
Última actividad el 4 de Oct. de 2023

Recently developed: a "microscope" based on touch and stereo vision.
Using touch removes the possibility of optical confusion -- for example, black on touch is only due to shape, not due to the possibility that the object has a black patch.
Sorry, you might need a Facebook account to watch the video.
Image Analyst
Image Analyst
Última actividad el 3 de Oct. de 2023

(Sorry - it should be 2023b by now.)
Mike Croucher
Mike Croucher
Última actividad el 10 de Mayo de 2024

Adam Danz
Adam Danz
Última actividad el 6 de Mzo. de 2024

I'm curious how the community uses the hold command when creating charts and graphics in MATLAB. In short, hold on sets up the axes to add new objects to the axes while hold off sets up the axes to reset when new objects are added.
When you use hold on do you always follow up with hold off? What's your reasoning on this decision?
Can't wait to discuss this here! I'd love to hear from newbies and experts alike!
The way we've solved ODEs in MATLAB has been relatively unchanged at the user-level for decades. Indeed, I consider ode45 to be as iconic as backslash! There have been a few new solvers in recent years -- ode78 and ode89 for example -- and various things have gotten much faster but if you learned how to solve ODEs in MATLAB in 1997 then your knowledge is still applicable today.
In R2023b, there's a completely new framework for solving ODEs and I love it! You might argue that I'm contractually obliged to love it since I'm a MathWorker but I can assure you this is the real thing!
The new interface makes a lot of things a much easier to do. Its also setting us up for a future where we'll be able to do some very cool algorithmic stuff behind the scenes.
Let me know what you think of the new functionality and what you think MathWorks should be doing next in the area of ODEs.
Rena Berman
Rena Berman
Última actividad el 11 de Oct. de 2023

To solve the puzzle, first unscramble each of the words on the left. Then rearrange the letters in the yellow shaded boxes to complete the sentence on the right.
If you enjoyed this puzzle let me know with a like or in the comments below and I'll post more of them. Please don't post your answer, or any hints, and spoil it for those who come across this puzzle after you!! If you want to check your answer, you can messge me your guess through the link on my profile card (click on my name, Rena Berman, above and then on the envelope icon in the top right corner of the profile card that appears).
Shore
Shore
Última actividad el 11 de Oct. de 2023

I wanted to write to my public channel 2278931 with 8 different values to 8 different gauge widgets.
Here is my link.
https://api.thingspeak.com/update.json?api_key=xxxxxxxxxxxxxxxx&field1=1&field2=2&field3=3&field4=4&field5=5&field6=6&field7=7&field8=8
You can change values and in the link to change gauge values. On edit I edited my write key to make it not work for others but it will work with your own key.
Daniel Bending
Daniel Bending
Última actividad el 26 de Sept. de 2023

Hi All,
I'm attempting to put a set of simbiology global sensitivity analysis plots into my thesis and I'm running into some issues with the GSA plots. Firstly, the figures are very large, it would be quite beneficial to grab a set of the plots and arrange them myself, is there any documentation on how to mess around with the '1x1 Sobol' produced by sbiosobol? Or just GSA plots in general.
The second problem is that the results appear to be relative to the most sensitive parameter in that run. Is it recommended to have a resonably sensitive 'baseline' parameter in each run? I find it difficult to compare plots when a not so sensitive parameter is being recorded as near '1' for the whole run because it's being stacked against a set of very insensitive parameters. I.e. if i have multiple sets of GSAs due to a large model, how can I easily compare results? If I could do some single run through with every parameter that would be the ideal, I imagine, but then the default plot would be half a mile off the bottom of my screen, haha! Perhaps there is a solution to the first question that might help there?
Thank you for your help,
Dan

Up until a few weeks ago, there was a "channels shared with me" option in Thingspeak. I was able to access the channel created by a different user, only once. The next time me and my groupmate tried to open the channel, there wasn't a "channels shared with me" option anymore. Why is that and how can this be resolved?