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Image Analyst
Image Analyst
Last activity on 24 Dec 2024 at 21:30

Attaching the Photoshop file if you want to modify the caption.

この場は MATLAB や Simulink を使っている皆さんが、気軽に質問や情報交換ができる場所として作られました。日本語でも気軽に投稿ができるように今回日本語チャネルを解説します。
ユーザーの皆様とのやり取りを通じて、みんなで知識や経験を共有し、一緒にスキルアップしていきましょう。 どうぞお気軽にご参加ください。
Thanks to Hernia Baby さん、Iwasato Takuya さん
そして日本語チャネル開設にあたってコメントくださった皆様、ありがとうございます!
Peter Fryscak
Peter Fryscak
Last activity on 24 Dec 2024 at 14:53

What better way to add a little holiday magic than the L-shaped membrane atop your evergreen? My colleagues output the shape and then added some thickness and an interior cylinder in Blender. Then, the shape was exported to STL and 3D printed (in several pieces). Then glued, sanded, primed, sanded again and painted. If you like, the STL file is attached. Thank you to https://blogs.mathworks.com/community/2013/06/20/paul-prints-the-l-shaped-membrane/ and a tip of the hat to MATLAB Ornament. Happy Holidays!
Steve Eddins
Steve Eddins
Last activity on 12 Dec 2024 at 21:25

Speaking as someone with 31+ years of experience developing and using imshow, I want to advocate for retiring and replacing it.
The function imshow has behaviors and defaults that were appropriate for the MATLAB and computer monitors of the 1990s, but which are not the best choice for most image display situations in today's MATLAB. Also, the 31 years have not been kind to the imshow code base. It is a glitchy, hard-to-maintain monster.
My new File Exchange function, imview, illustrates the kind of changes that I think should be made. The function imview is a much better MATLAB graphics citizen and produces higher quality image display by default, and it dispenses with the whole fraught business of trying to resize the containing figure. Although this is an initial release that does not yet support all the useful options that imshow does, it does enough that I am prepared to stop using imshow in my own work.
The Image Processing Toolbox team has just introduced in R2024b a new image viewer called imageshow, but that image viewer is created in a special-purpose window. It does not satisfy the need for an image display function that works well with the axes and figure objects of the traditional MATLAB graphics system.
I have published a blog post today that describes all this in more detail. I'd be interested to hear what other people think.
Note: Yes, I know there is an Image Processing Toolbox function called imview. That one is a stub for an old toolbox capability that was removed something like 15+ years ago. The only thing the toolbox imview function does now is call error. I have just submitted a support request to MathWorks to remove this old stub.
The int function in the Symbolic Toolbox has a hold/release functionality wherein the expression can be held to delay evaluation
syms x I
eqn = I == int(x,x,'Hold',true)
eqn = 
which allows one to show the integral, and then use release to show the result
release(eqn)
ans = 
I think I already submitted an enhancement request for the same functionality for symsum.
Maybe it would be nice to be able to hold/release any symbolic expression to delay the engine from doing evaluations/simplifications that it typically does. For example:
x*(x+1)/x, sin(sym(pi)/3)
ans = 
ans = 
If I'm trying to show a sequence of steps to develop a result, maybe I want to explicitly keep the x/x in the first case and then say "now the x in the numerator and denominator cancel and the result is ..." followed by the release command to get the final result.
Perhaps held expressions could even be nested to show a sequence of results upon subsequent releases.
Held expressions might be subject to other limitations, like maybe they can't be fplotted.
Seems like such a capability might not be useful for problem solving, but might be useful for exposition, instruction, etc.
Watt's Up with Electric Vehicles?EV modeling Ecosystem (Eco-friendly Vehicles), V2V Communication and V2I communications thereby emitting zero Emissions to considerably reduce NOx ,Particulates matters,CO2 given that Combustion is always incomplete and will always be.
Reduction of gas emissions outside to the environment will improve human life span ,few epidemic diseases and will result in long life standard
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!
Image Analyst
Image Analyst
Last activity on 2 Dec 2024 at 22:14

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.)
Image Analyst
Image Analyst
Last activity on 7 Nov 2024

It would be nice to have a function to shade between two curves. This is a common question asked on Answers and there are some File Exchange entries on it but it's such a common thing to want to do I think there should be a built in function for it. I'm thinking of something like
plotsWithShading(x1, y1, 'r-', x2, y2, 'b-', 'ShadingColor', [.7, .5, .3], 'Opacity', 0.5);
So we can specify the coordinates of the two curves, and the shading color to be used, and its opacity, and it would shade the region between the two curves where the x ranges overlap. Other options should also be accepted, like line with, line style, markers or not, etc. Perhaps all those options could be put into a structure as fields, like
plotsWithShading(x1, y1, options1, x2, y2, options2, 'ShadingColor', [.7, .5, .3], 'Opacity', 0.5);
the shading options could also (optionally) be a structure. I know it can be done with a series of other functions like patch or fill, but it's kind of tricky and not obvious as we can see from the number of questions about how to do it.
Does anyone else think this would be a convenient function to add?
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/
In the past two years, large language models have brought us significant changes, leading to the emergence of programming tools such as GitHub Copilot, Tabnine, Kite, CodeGPT, Replit, Cursor, and many others. Most of these tools support code writing by providing auto-completion, prompts, and suggestions, and they can be easily integrated with various IDEs.
As far as I know, aside from the MATLAB-VSCode/MatGPT plugin, MATLAB lacks such AI assistant plugins for its native MATLAB-Desktop, although it can leverage other third-party plugins for intelligent programming assistance. There is hope for a native tool of this kind to be built-in.
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)
ans = logical
1
fnh(15)
ans = logical
0
fnh(101)
ans = logical
1
fnh(1000)
ans = logical
0
Feel free to try/modify the incantation yourself. Happy Halloween!
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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初カキコ…ども… 俺みたいな中年で深夜にMATLAB見てる腐れ野郎、 他に、いますかっていねーか、はは
今日のSNSの会話 あの流行りの曲かっこいい とか あの 服ほしい とか ま、それが普通ですわな
かたや俺は電子の砂漠でfor文無くして、呟くんすわ
it'a true wolrd.狂ってる?それ、誉め 言葉ね。
好きなtoolbox Signal Processing Toolbox
尊敬する人間 Answersの海外ニキ(学校の課題質問はNO)
なんつってる間に4時っすよ(笑) あ~あ、休日の辛いとこね、これ
-----------
ディスカッションに記事を書いたら謎の力によって消えたっぽいので、性懲りもなくだらだら書いていこうと思います。前書いた内容忘れたからテキトーに書きます。
救いたいんですよ、Centralを(倒置法)
いっぬはMATLAB Answersに育てられてキャリアを積んできたんですよ。暇な時間を見つけてはAnswersで回答して承認欲求を満たしてきたんです。わかんない質問に対しては別の人が回答したのを学び、応用してバッジもらったりしちゃったりしてね。
そんな思い出の大事な1ピースを担うMATLAB Centralが、いま、苦境に立たされている。僕はMATLAB Centralを救いたい。
最悪、救うことが出来なくともCentralと一緒に死にたい。Centralがコミュニティを閉じるのに合わせて、僕の人生の幕も閉じたい。MATLABメンヘラと呼ばれても構わない。MATLABメンヘラこそ、MATLABに対する愛の証なのだ。MATLABメンヘラと呼ばれても、僕は強く生きる。むしろ、誇りに思うだろう。
こうしてMATLABメンヘラへの思いの丈を精一杯綴った今、僕はこう思う。
MATLABメンヘラって何?
なぜ苦境に立っているのか?
生成AIである。Hernia Babyは激怒した。必ず、かの「もうこれでいいじゃん」の王を除かなければならぬと決意した。Hernia BabyにはAIの仕組みがわからぬ。Hernia Babyは、会社の犬畜生である。マネージャが笛を吹き、エナドリと遊んで暮して来た。けれどもネットmemeに対しては、人一倍に敏感であった。
冗談はさておき、Stack Overflowでは生成AIによってトラフィック(質問数や参加人数等)が減ってきているそうです。(参考:The Fall of Stack Overflow)
風の噂によるとMATLAB Answersの質問数も微妙に減少傾向にあるそうな。
確かにTwitter(現X)でもAnswers botの呟き減ったような…。
ゆ、許せんぞ生成AI…!
とか言ってたらちゃっかりAI Chat Playgroundなんて出しちゃうMathWorks。逞しいね!
MATLAB Centralは日本では流行ってない?
そもそもCentralって日本じゃあまりアクセスされてないんじゃなイカ?
だってどうやってここにたどり着けばいいかわかんねえもん!(暴言)
MATLABのHPにはないから一回コミュニティのプロファイル入って…
やっと表示される。気づかんって!
MATLAB Centralは無料で学べる宝物庫
とはいえ本当にオススメなんです。
どんなのがあるかさらっと紹介していきます。
ここは短い文章で問題を解くコードを書き上げるところ。
多様な分野を実践的に学ぶことができるし、何より他人のコードも見ることができる。
たまにそんなのありかよ~って回答もあるけどいい訓練になる。
ただ英語の問題見たらさ~ 悪い やっぱつれぇわ…
我らがアイドルmichioニキやJiro氏が新機能について紹介なんかもしてくれてる。
なんだかんだTwitter(現X)で紹介しちゃってるから、見るのさぼったり…ゲフンゲフン!
定期的に開催される。
プライズも貰えたりするし、何よりめっちゃ面白い作品を皆が書いてくる。
個人的にはマンタのアニメがめっちゃキテる。
ちなみに僕は過去にウンチを作ったが海外ニキたちにはソフトクリームじゃないのか?と伝わらなくて涙を流したことがある。
p=pi;
l = 5e3;
m = 0:l;
[u,v]=meshgrid(10*m/l*p,2*m/l*p);
c=cos(v/2);
s=sin(v);
e=1-exp(u/(6*p));
surf(2*e.*cos(u).*c.^2,-e*2.*sin(u).*c.^2,1-exp(u/(3.75*p))-s+exp(u/(5.5*p)).*s,'FaceColor','#a47a43','EdgeAlpha',0.02)
axis equal off
A=7.3;
zlim([-A 0])
view([-12 23])
set(gcf,'Color','#d2b071')
過去の事は水に流してくれないか?
toolboxにない自作関数とかを無料で皆が公開してるところ。
MATLABのアドオンからだと関数をそのままインストール出来たりする。
だいたいの答えはここにある。質問する前にググれば出てくる。
躓いて調べると過去に書いてあった自分の回答に助けられたりもする。
for文で回答すると一定数の海外ニキたちが
と絡んでくる。
Answersがバキバキ回答する場であるのに対して、ここでは好きなことを呟いていいらしい。最近できたっぽい。全然知らんかった。海外では「こんな機能欲しくね?」とかけっこう人気っぽい。
日本人が書いてないから僕がこんなクソスレ書いてるわけ┐(´д`)┌ヤレヤレ
まとめ
いかがだったでしょうか?このようにCentralは学びとして非常に有効な場所なのであります。インプットもいいけど是非アウトプットしてみましょう。コミュニティはアカウントさえ持ってたら無料でやれるんでね。
皆はどうやってMATLAB/Simulinkを学んだか、良ければ返信でクソレスしてくれると嬉しいです。特にSimulinkはマジでな~んにもわからん。MathWorksさんode45とかソルバーの説明ここでしてくれ。
後、ディスカッション一時保存機能つけてほしい。
最後に
Centralより先に、俺を救え
If I go to a paint store, I can get foldout color charts/swatches for every brand of paint. I can make a selection and it will tell me the exact proportions of each of base color to add to a can of white paint. There doesn't seem to be any equivalent in MATLAB. The common word "swatch" doesn't even exist in the documentation. (?) One thinks pcolor() would be the way to go about this, but pcolor documentation is the most abstruse in all of the documentation. Thanks 1e+06 !
As pointed out in Doxygen comments in code generated with Simulink Embedded Coder - MATLAB Answers - MATLAB Central (mathworks.com), it would be nice that Embedded Coder has an option to generate Doxygen-style comments for signals of buses, i.e.:
/** @brief <Signal desciption here> **/
This would allow static analysis tools to parse the comments. Please add that feature!