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I am very excited to share my new book "Data-driven method for dynamic systems" available through SIAM publishing: https://epubs.siam.org/doi/10.1137/1.9781611978162
This book brings together modern computational tools to provide an accurate understanding of dynamic data. The techniques build on pencil-and-paper mathematical techniques that go back decades and sometimes even centuries. The result is an introduction to state-of-the-art methods that complement, rather than replace, traditional analysis of time-dependent systems. One can find methods in this book that are not found in other books, as well as methods developed exclusively for the book itself. I also provide an example-driven exploration that is (hopefully) appealing to graduate students and researchers who are new to the subject.
Each and every example for the book can be reproduced using the code at this repo: https://github.com/jbramburger/DataDrivenDynSyst
Hope you like it!
Christmas season is underway at my house:
(Sorry - the ornament is not available at the MathWorks Merch Shop -- I made it with a 3-D printer.)
I am using the ELECFREAKS IOT:bit Expansion Board with micro:bit to record data, it worked normally but in this week I tested again, and discover no data is uploaded to the channel ie.no entries in channel. The code in makecode are the same as before and the wifi is work, I cannot find the reason that cause this failure.
I am using the free option with 4 channels available. I do not have any channels listed, but when I want to create a new channel it gives me an error massage to say that I have used up my 4 channels and need to purchase units to create additional channels.
Hello
I have 3 devices (IOT board using SIM7600 module) sending one value to Thingsspeak. Have been working just fine a couple of years. However 14/11-24 I receive http error code 406 for all 3 devices.
The http get is working just fine when testing directly in the browser (https://api.thingspeak.com/update?api_key=xxxxx&field1=33), the server return the entrie number.
However, when running the same address via SIM7600 I receive - +HTTPACTION: 0,406,0
Any tips for the 406 error code?
Hello, I am wondering why I have over 12000 messages (writes)per day to a channel which I only update all 8 fields every 20 minutes. Or are these statistic timely delayed? Since testing I might have more writes, but now with my ready weather station only every 20 minutes my data will be updated. Wetterbox Channel ID: 2391212 Access: Public Can you explain this to me? Thank you for your help. Regards, Julian
My favorite image processing book is The Image Processing Handbook by John Russ. It shows a wide variety of examples of algorithms from a wide variety of image sources and techniques. It's light on math so it's easy to read. You can find both hardcover and eBooks on Amazon.com Image Processing Handbook
There is also a Book by Steve Eddins, former leader of the image processing team at Mathworks. Has MATLAB code with it. Digital Image Processing Using MATLAB
You might also want to look at the free online book http://szeliski.org/Book/
I am considering to upgrade to HOME license. Does the HOME license provides more widgets (including a text message widget), in addition to the 4 basic widgets in the FREE version?
I know we have all been in that all-too-common situation of needing to inefficiently identify prime numbers using only a regular expression... and now Matt Parker from Standup Maths helpfully released a YouTube video entitled "How on Earth does ^.?$|^(..+?)\1+$ produce primes?" in which he explains a simple regular expression (aka Halloween incantation) which matches composite numbers:
Here is my first attempt using MATLAB and Matt Parker's example values:
fnh = @(n) isempty(regexp(repelem('*',n),'^.?$|^(..+?)\1+$','emptymatch'));
fnh(13)
fnh(15)
fnh(101)
fnh(1000)
Feel free to try/modify the incantation yourself. Happy Halloween!
Hi,
I don't know why really. Why is there seems a difference between daily average that calculated with .csv file that has exported directly from the channel.
and calculation with the ThingSpeak Daily Average API, there is a lot of difference at the moment.
Why does this happens, and how should I fix this issue?
Attached image file is daily average that has been retrived through the API,
And attached excel file is raw data from the channel.
Thank you.
Hello! The MathWorks Book Program is thrilled to welcome you to our discussion channel dedicated to books on MATLAB and Simulink. Here, you can:
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We’re excited to see the discussions and exchanges that will unfold here. Whether you're an expert or beginner, there's a place for you in our community. Let's embark on this journey together!
My Licensed avvount has expired. When I go to my expired license page, I select "Revert To Free Account", I get the following message:
Only administrators of this license are allowed to renew units on this ThingSpeak license. If you want to continue to collect data in your ThingSpeak channels, contact your license administrator.
Aren't I the license administrator? or do I need to contact someone at Thingspeak/MathWorks?
Hi, My data send to thingspeak is not received/updated for the last 6 hours on the charts and dials. All worked well till about 6 hour ago. I am using Node-red and the API Url: https://thingspeak.com
Any help please?
Greetings Gert
To solve issues around the browsers blocking 3p cookies and having different behavior across different browsers, the ThingSpeak website is now served from https://thingspeak.mathworks.com. There are no changes required from devices or users. Just log in and use the service as you always did.
I left the code unchanged, modifying only secrets.h.
I am using an ESP32-WROOM -32U
Connection to network succeeds, but ThingSpeak.writeFields fails every time, with HTTP error code 400.
The sketch I am really trying to use is loosely based on this example, accesses Time and Weather info with no problems, but ThingSpeak.writeFields fails with HTTP error code 301.
This is my first attempt to use ThingSpeak.
Is this example sketch still valid, or must I look elsewhere? Suggestions please.
Hi everyone,
I'm working on a school project where I need to send sensor data from my Arduino to a Power BI REST API using ThingsHTTP. I've been trying to get this to work, but I'm running into errors like this:
{"error":{"code":"InvalidRequest","message":"Error parsing request for dataset sobe_wowvirtualserver|a7b68fb5-533b-471f-a5da-3bdd6746ee16: Conversion error on column '<pi>pH</pi>': <pi>Input string was not in a correct format.</pi>"}}
I'm a beginner with this, and I'm not sure what I'm doing wrong. What steps should I take to resolve this issue? Also, does anyone know the correct format for an HTTP request body when sending dynamic sensor data?
This is the body format I'm trying to send to Power BI:
[
{
"pH": 98.6,
"TDS": 98.6,
"turbidity": 98.6,
"temperature": 98.6
}
]
Any advice on how to construct the HTTP body with values that change over time would be greatly appreciated! Thanks in advance!"
hope this message finds you well. I am currently working on a project involving the design and numerical simulation of metalenses using Zemax and MATLAB. The design phase involves saving phase data from the Zemax simulation, which is later used in a numerical script to generate the metalens in MATLAB.
I have a MATLAB file that contains the phase data saved from Zemax, but I am unsure of the specific method or format used to extract and save the data from Zemax. The phase data I currently have in MATLAB is as follows:
- Phase matrix: 571 x 571 (double)
- X data: 571 x 1 (double)
- Y data: 571 x 1 (double)
Could you please provide guidance on:
- How this phase data was likely saved from Zemax into MATLAB?
- What steps or scripts were used to extract this information from the design, particularly the 571 x 571 phase matrix and the corresponding X and Y data?
- Any best practices or tools available in Zemax for exporting such data?
This information will help me reproduce the workflow and proceed with my analysis.
Thank you for your support. I look forward to your guidance.
Best regards,
Zaka
I went to perform an IoT for an automated plantation but the same error always occurs to me when I upload it to the mcu node, which is: Connection to ThingSpeak failed.
