Contenuto principale

Risultati per

Missed the Cody World Cup Watch Party on March 27—or want to relive the glory?
The full recording is now available, and it’s every bit as entertaining as it was live.
What you’ll see in the video:
🔥 Top MATLAB users in action
Watch expert solvers think, debug, strategize—and occasionally panic.
Which functions do they reach for? How do they break down the problem?
BEHOLD the power moves… and the 3D arrays.
🏆 Three teams. Six champions. One viciously clever problem.
There may have been NaN traps.
There may have been nested for‑loops.
There may have been… emotions.
🎙️ Professional‑grade commentary by:
@Ned Gulley – Capricious dictator, Lord Ned
@Matt Tearle – Architect of Diabolical Challenges
Their line‑by‑line play‑by‑play turns MATLAB into a true spectator sport.
👉Watch the recording here and take a shot at the Champion-level problem yourself.
Finally, tell us what you want to see next—head‑to‑head contests? Team battles? Drop your ideas in the comments. All suggestions welcome!
This is a reminder that the Cody World Cup Watch Party takes place on March 27 at 10:00 AM ET.
We’ll watch how top MATLAB minds solve a fun‑but‑challenging Cody championship‑round problem, followed by a live open discussion with the players.
📅 To join, download the ics calendar file (link updated and no sign‑in required) or copy the meeting link and add it to your calendar!
📌 Full details, agenda, and prep suggestions are in the original announcement.
You’re invited to the Cody World Cup Watch Party! Six of the world’s best MATLAB users have advanced to the Cody Contest 2025 Bonus Round to tackle a championship-level Cody problem. Now it’s your chance to watch, learn, and interact with those pros!
📅When & How to Join
Date: March 27, 2026
Time: 10:00 AM Eastern Time
Where: Microsoft Teams (download the ics calendar file or copy the meeting link and add it to your calendar!)
📽 Agenda
Part 1 – Watch Together (25 min)
Watch how those top MATLAB users think, debug, strategize, and occasionally panic😅. Enjoy professional-grade commentary from MathWorks experts as the action unfolds.
Part 2 – Live Discussion (35 min)
Chat directly with those top minds and the problem creator, @Matt Tearle! Reply in the comments with questions you’d like us to ask them.
🧩 Solve the Problem Yourself!
For the best experience, try that Cody problem yourself before the event. Trust us — the discussions are way more fun after you’ve wrestled with it.
Whether you are a beginner or a seasoned expert, this is your chance to see the best in action, pick up MATLAB tips, and have some fun. See you there!
The Cody Contest 2025 has officially wrapped up! Over the past 4 weeks, more than 700 players submitted over 20,000 solutions. In addition, participants shared 20+ high-quality Tips & Tricksarticles—resources that will benefit Cody users for years to come.
Now it’s time to announce the winners.
🎉 Week 4 winners:
Weekly Prizes for Contest Problem Group Finishers:
Weekly Prizes for Contest Problem Group Solvers:
Weekly Prizes for Tips & Tricks Articles:
This week’s prize goes to @WANG Zi-Xiang. See the comments from our judge and problem group author @Matt Tearle:
‘We had a lot of great tips for solving Cody problems in general and the contest problems specifically. But we all know there are those among us who, having solved the problem, still want to tinker and make their code better. There are different definitions of "better", but code size remains the base metric in Cody. Enter Wang Zi-Xiang who compiled a list of many tips for reducing Cody size. This post also generated some great discussion (even prompting our insane autocrat, Lord Ned himself, to chime in). I particularly like the way that, while reducing Cody size often requires some arcane tricks that would normally be considered bad coding practice, the intellectual activity of trying to "game the system" makes you consider different programming approaches, and sometimes leads you to learn corners of MATLAB that you didn't know.’
🏆 Grand Prizes for the Main Round
Team Relentless Coders:
1st Place: @Boldizsar
2nd Place: @Roberto
Team Creative Coders:
1st Place: @Mehdi Dehghan
2nd Place: @Vasilis Bellos
3rd Place: @Alaa
Team Cool Coders
1st Place: @Hong Son
2nd Place: @Norberto
3rd Place: @Maxi
Congratulations to all! Securing a top position on the leaderboard requires not only advanced MATLAB skills but also determination and consistency throughout the four-week contest. You will receive Amazon gift cards.
🥇 Winning Team
The competition was incredibly tight—we even had to use the tie-breaker rule.
Both Team Cool Coders and Team Relentless Coders achieved 16 contest group finishers. However, the last finisher on Cool Coders completed the problem group at 1:02 PM on Dec 7, while the last finisher on Relentless Coders finished at 9:47 PM the same day.
Such a close finish! Congratulations to Team Cool Coders, who have earned the Winning Team Finishers badge.
🎬 Bonus Round
Invitations have been sent to the 6 players who qualified for the Bonus Round. Stay tuned for updates—including the Big Watch Party afterward!
Congratulations again to all winners! We’ll be reaching out after the contest ends. It has been an exciting, rewarding, and knowledge-packed journey.
See you next year!
Over the past three weeks, players have been having great fun solving problems, sharing knowledge, and connecting with each other. Did you know over 15,000 solutions have already been submitted?
This is the final week to solve Cody problems and climb the leaderboard in the main round. Remember: solving just one problem in the contest problem group gives you a chance to win MathWorks T-shirts or socks.
🎉 Week 3 Winners:
Weekly Prizes for Contest Problem Group Finishers:
Weekly Prizes for Contest Problem Group Solvers:
@森緒, @R, @Javier, @Shubham Shubham, @Jiawei Gong
Weekly Prizes for Tips & Tricks Articles:
This week’s prize goes to @Cephas. See the comments from our judge and problem group author @Matt Tearle:
'Some folks have posted deep dives into how to tackle specific problems in the contest set. But others have shared multiple smaller, generally useful tips. This week, I want to congratulate the cumulative contribution of Cool Coder Cephas, who has shared several of my favorite MATLAB techniques, including logical indexing, preallocation, modular arithmetic, and more. Cephas has also given some tips applying these MATLAB techniques to specific contest problems, such as using a convenient MATLAB function to vectorize the Leaderboard problem. Tip for Problem 61059 – Leaderboard for the Nedball World Cup:'
Congratulations to all Week 3 winners! Let’s carry this momentum into the final week!
In just two weeks, the competition has become both intense and friendly as participants race to climb the team leaderboard, especially in Team Creative, where @Mehdi Dehghan currently leads with 1400+ points, followed by @Vasilis Bellos with 900+ points.
There’s still plenty of time to participate before the contest's main round ends on December 7. Solving just one problem in the contest problem group gives you a chance to win MathWorks T-shirts or socks. Completing the entire problem group not only boosts your odds but also helps your team win.
🎉 Week 2 Winners:
Weekly Prizes for Contest Problem Group Finishers:
Weekly Prizes for Contest Problem Group Solvers:
Weekly Prizes for Tips & Tricks Articles:
This week’s prize goes to @Athi for the highly detailed post Solving Systematically The Clueless - Lord Ned in the Game Room.
Comment from the judge:
Shortly after the problem set dropped, several folks recognized that the final problem, "Clueless", was a step above the rest in difficulty. So, not surprisingly, there were a few posts in the discussion boards related to how to tackle this problem. Athi, of the Cool Coders, really dug deep into how the rules and strategies could be turned into an algorithm. There's always more than one way to tackle any difficult programming problem, so it was nice to see some discussion in the comments on different ways you can structure the array that represents your knowledge of who has which cards.
Congratulations to all Week 2 winners! Let’s keep the momentum going!
In just one week, we have hit an amazing milestone: 500+ players registered and 5000+ solutions submitted! We’ve also seen fantastic Tips & Tricks articles rolling in, making this contest a true community learning experience.
And here’s the best part: you don’t need to be a top-ranked player to win. To encourage more casual and first-time players to jump in, we’re introducing new weekly prizes starting Week 2!
New Casual Player Prizes:
  • 5 extra MathWorks T-shirts or socks will be awarded every week.
  • All you need to qualify is to register and solve one problem in the Contest Problem Group.
Jump in, try a few problems, and don’t be shy to ask questions in your team’s channel. You might walk away with a prize!
Week 1 Winners:
Weekly Prizes for Contest Problem Group Finishers:
Weekly Prizes for Tips & Tricks Articles:
Week 1 winner for best Tips & Tricks Articles is @Vasilis Bellos.
Contest problems author @Matt Tearle commented:
We had a lot of people share useful tips (including some personal favorite MATLAB tricks). But Vasilis Bellos went *deep* into the Bridges of Nedsburg problem. Fittingly for a Creative Coder, his post was innovative and entertaining, while also cleverly sneaking in some hints on a neat solution method that wasn't advertised in the problem description.
Congratulations to all Week 1 winners! Prizes will be awarded after the contest ends. Let’s keep the momentum going!
What a fantastic start to Cody Contest 2025! In just 2 days, over 300 players joined the fun, and we already have our first contest group finishers. A big shoutout to the first finisher from each team:
  • Team Creative Coders: @Mehdi Dehghan
  • Team Cool Coders: @Pawel
  • Team Relentless Coders: @David Hill
  • 🏆 First finisher overall: Mehdi Dehghan
Other group finishers: @Bin Jiang (Relentless), @Mazhar (Creative), @Vasilis Bellos (Creative), @Stefan Abendroth (Creative), @Armando Longobardi (Cool), @Cephas (Cool)
Kudos to all group finishers! 🎉
Reminder to finishers: The goal of Cody Contest is learning together. Share hints (not full solutions) to help your teammates complete the problem group. The winning team will be the one with the most group finishers — teamwork matters!
To all players: Don’t be shy about asking for help! When you do, show your work — include your code, error messages, and any details needed for others to reproduce your results.
Keep solving, keep sharing, and most importantly — have fun!
The main round of Cody Contest 2025 kicks off today! Whether you’re a beginner or a seasoned solver, now’s your time to shine.
Here’s how to join the fun:
  • Pick your team — choose one that matches your coding personality.
  • Solve Cody problems — gain points and climb the leaderboard.
  • Finish the Contest Problem Group — help your team win and unlock chances for weekly prizes by finishing the Cody Contest 2025 problem group.
  • Share Tips & Tricks — post your insights to win a coveted MathWorks Yeti Bottle.
  • Bonus Round — 2 players from each team will be invited to a fun live code-along event!
  • Watch Party – join the big watch event to see how top players tackle Cody problems
Contest Timeline:
  • Main Round: Nov 10 – Dec 7, 2025
  • Bonus Round: Dec 8 – Dec 19, 2025
Big prizes await — MathWorks swag, Amazon gift cards, and shiny virtual badges!
We look forward to seeing you in the contest — learn, compete, and have fun!
作ったコードは公開して使ってもらいましょう!ということでその方法をブログで紹介します。
GitHub や File Exchange で公開しているコードがあれば、ぜひこのスレで教えてください!
ブログで紹介している大まかな3ステップをここにまとめます。
1. GitHub でコードを公開・開発する
  • GitHub 上でのリポジトリ公開はコミュニティ形成にもつながります。
  • R2025a 以降は MATLAB の Markdown サポートも強化されており、README.md を充実させると理解や導入が促進されます。
2. File Exchange に展開(GitHub と連携して自動同期)
  • File Exchangeで公開することで MATLAB 内から検索・インストールが可能になります。
  • GitHub と File Exchange の連携設定により、GitHub の更新を自動的に File Exchange に反映させることも可能です。
3. 「Open in MATLAB Online」ボタンやリンクを追加
  • GitHub リポジトリに「Open in MATLAB Online」リンクやボタンを埋め込むことで、ブラウザ上でコードを試せます。
群馬産業技術センター様をお招きし、製造現場での異常検知の取り組みについてご紹介いただくオンラインセミナーを開催します。
実際の開発事例を通して、MATLABを使った「教師なし」異常検知の進め方や、予知保全に役立つ最新機能もご紹介します。
✅ 異常検知・予知保全に興味がある方
✅ データ活用を何から始めればいいか迷っている方
✅ 実際の現場事例を知りたい方
ぜひお気軽にご参加ください!
Simulinkモデルを生成AIで自動的に作成できたら便利だと思いませんか?
QiitaのSacredTubesさんは、このアイデアを実験的に試みた記事を公開しています。
その方法は、まず生成AIでVerilogコードを作成し、それをSimulinkに取り込んでモデル化するというものです。(ここではHDL Coderというツールボックスの機能が使われました:importhdl
まだ実用段階には至っていませんが、モデルベース開発(MBD)と生成AIの可能性を探る上で、非常に興味深い試みです。
生成AIの限界と可能性を考えるきっかけとして、一読の価値があります。
---
もし「Simulink Copilot」のような生成AIツールが登場するとしたら、
どんな機能があったら嬉しいと思いますか?
  • 自然言語でブロック図を生成?
  • 既存モデルの自動ドキュメント化?
  • シミュレーション結果の要約と解釈?
皆さんのアイデアをぜひシェアしてください!
毎回 MATLAB を立ち上げたときに実行される startup,閉じるときに実行される finish って使ってますか?
久々に startup.m を開いてみたら
format short
format compact
disp("Ready")
の3行がありました.何らかの理由で format 設定を変えたとしても次回起動したときにはお気に入りの format に戻っているというのは嬉しいですよね!
disp("Ready")
は特に意味はありませんが,表示されると「さあ,始めよう!」って気分になります.(笑)
  • 昨日までちゃんと動いていたのに・・
  • ヘルプページ通りに書いているのに・・
MATLAB 関数がエラーを出すようになることありますよね(?)そんな時にみなさんがまず確認するもの、何かありますか?教えてください!
自分がまず試すのはこれ:which 。うっかり同じ名前の関数や変数を作っちゃっているかどうかを確認できます。
例えば
which -all plot
をコマンドウィンドウで実行して、もともと MATLAB で定義されている plot 関数(MATLAB のインストールフォルダにある plot 関数)がちゃんと頭に出てくるかどうか確認します。
キーと値の組み合わせでデータを格納できるディクショナリ。R2022bdictionaryコマンドが登場し、最近のバージョンではreaddictionarywritedictionaryJSONファイルからの読み込み・書き込みにも対応しました。
私はMIDIデータからピアノの演奏動画を作るプログラムで、ディクショナリを使いました。音のノート番号をキーにして、patchで白と黒で鍵盤を塗りつぶしたmatlab.graphics.Graphicsデータ型を値にしたディクショナリで保存して、MIDIで鳴らされた音のノート番号からlookupでグラフのオブジェクトを取得し、FaceColorを変更してハイライトするというもの。
コード例
%% MIDIデータの.matファイルを読み取ってピアノを描画するサンプル
fig = figure('Position', [34 328 1626 524]);
ax = axes;
whiteKeyY = [0 0 150 150];
whiteKeyColor = [1 1 1];
blackKeyY = [50 50 150 150];
blackKeyColor = [0.1 0.1 0.1];
edgeColor = [0 0 0];
% ディクショナリの定義
d = configureDictionary("double", "matlab.graphics.Graphics");
% 白鍵を描画
for n = 1:9
pos = 23*7*(n-1);
d = insert(d, 21 + (n-1)*12, patch([pos+5 pos+28 pos+28 pos+5],whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 21 + (n-1)*12));
d = insert(d, 23 + (n-1)*12, patch([pos+28 pos+51 pos+51 pos+28], whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 23 + (n-1)*12));
d = insert(d, 24 + (n-1)*12, patch([pos+51 pos+74 pos+74 pos+51], whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 24 + (n-1)*12));
if n < 9
d = insert(d, 26 + (n-1)*12, patch([pos+74 pos+97 pos+97 pos+74], whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 26 + (n-1)*12));
d = insert(d, 28 + (n-1)*12, patch([pos+97 pos+120 pos+120 pos+97], whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 28 + (n-1)*12));
d = insert(d, 29 + (n-1)*12, patch([pos+120 pos+143 pos+143 pos+120], whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 29 + (n-1)*12));
d = insert(d, 31 + (n-1)*12, patch([pos+143 pos+166 pos+166 pos+143], whiteKeyY, whiteKeyColor, 'EdgeColor', edgeColor, 'UserData', 31 + (n-1)*12));
end
end
% 黒鍵を描画。白鍵の上になるようにループを分けています
for n = 1:9
pos = 23*7*(n-1);
d = insert(d, 22 + (n-1)*12, patch([pos+23 pos+33 pos+33 pos+23], blackKeyY, blackKeyColor, 'EdgeColor', [0 0 0], 'UserData', 22 + (n-1)*12));
if n < 9
d = insert(d, 25 + (n-1)*12, patch([pos+69 pos+79 pos+79 pos+69], blackKeyY, blackKeyColor, 'EdgeColor', [0 0 0], 'UserData', 25 + (n-1)*12));
d = insert(d, 27 + (n-1)*12, patch([pos+92 pos+102 pos+102 pos+92], blackKeyY, blackKeyColor, 'EdgeColor', [0 0 0], 'UserData', 27 + (n-1)*12));
d = insert(d, 30 + (n-1)*12, patch([pos+138 pos+148 pos+148 pos+138], blackKeyY, blackKeyColor, 'EdgeColor', [0 0 0], 'UserData', 30 + (n-1)*12));
d = insert(d, 32 + (n-1)*12, patch([pos+161 pos+171 pos+171 pos+161], blackKeyY, blackKeyColor, 'EdgeColor', [0 0 0], 'UserData', 32 + (n-1)*12));
end
end
xticklabels({})
yticklabels({})
xlim([5 1362])
drawnow
%% MIDI音源の.matファイルを読み込み
matData = load('fur-elise.mat');
msg = matData.receivedMessages;
eventTimes = [msg.Timestamp] - msg(1).Timestamp;
n = 1;
numNotes = 0;
lastNote = 0;
highlightedCircles = cell(1, 127);
% 音が鳴った鍵盤だけハイライトする
tic
while toc < max(eventTimes)
if toc > eventTimes(n)
thisMsg = msg(n);
if thisMsg.Type == "NoteOn"
numNotes = numNotes + 1;
lastNote = thisMsg.Note;
thisPatch = lookup(d, thisMsg.Note);
thisPatch.FaceColor = '#CCFFCC';
drawnow
elseif thisMsg.Type == "NoteOff"
numNotes = 0;
thisPatch = lookup(d, thisMsg.Note);
[~, ~, wOrB] = calcNotePos(thisMsg.Note);
if wOrB == "w"
thisPatch.FaceColor = 'white';
else
thisPatch.FaceColor = 'black';
end
drawnow
end
n = n+1;
end
end
%% サブ関数
function [pianoPos, centerPos, wOrB] = calcNotePos(note)
tempVar = idivide(int64(note), int64(12)); % 12で割った商
pos = 23*7*(tempVar-1);
switch mod(note, 12)
case 0 % C
pianoPos = pos + 62.5;
centerPos = 30;
wOrB = "w";
case 2 % D
pianoPos = pos + 85.5;
centerPos = 30;
wOrB = "w";
case 4 % E
pianoPos = pos + 108.5;
centerPos = 30;
wOrB = "w";
case 5 % F
pianoPos = pos + 131.5;
centerPos = 30;
wOrB = "w";
case 7 % G
pianoPos = pos + 154.5;
centerPos = 30;
wOrB = "w";
case 9 % A
pianoPos = pos + 177.5;
centerPos = 30;
wOrB = "w";
case 11 % B
pianoPos = pos + 200.5;
centerPos = 30;
wOrB = "w";
case 1 % C#
pianoPos = pos + 69;
centerPos = 100;
wOrB = "b";
case 3 % D#
pianoPos = pos + 92;
centerPos = 100;
wOrB = "b";
case 6 % F#
pianoPos = pos + 138;
centerPos = 100;
wOrB = "b";
case 8 % G#
pianoPos = pos + 161;
centerPos = 100;
wOrB = "b";
case 10 % A#
pianoPos = pos + 184;
centerPos = 100;
wOrB = "b";
end
end
皆さんはディクショナリを使ってますか? もし使っていたら、どういう活用をしているか、聞かせてください!
どの方法を使う事が多いですか?他によく使う方法があれば教えてくださいー。
方法①
Livescript 上で for ループ内で描画を編集させて描いた動画は「アニメーションのエクスポート」から動画ファイルに出力するのが一番簡単ですね。再生速度やら細かい設定ができない点は要注意。
方法②
exportgraphics 関数で "Append" オプション指定で実現できるようになった(R2022a から)のでこれも便利ですね。
下の例では、ループで新規データを追加してアニメーションを作成するのに Animatedlineオブジェクト を使い、データの追加には addpoints を使用。
N = 100;
x = linspace(0,4*pi,N);
y = sin(x);
filename = 'animation_sample.gif'; % Specify the output file name
if exist(filename,'file')
delete(filename)
end
h = animatedline;
axis([0,4*pi,-1,1]) % x軸の表示範囲を固定
for k = 1:length(x)
addpoints(h,x(k),y(k)); % ループでデータを追加
exportgraphics(gca,filename,"Append",true)
end
方法③
R2021b 以前のバージョンだとこんな感じ。
各ループで画面キャプチャして、imwrite で動画ファイルにフレーム追加していくイメージです。"DelayTime" を使って細かい指定ができるので、必要に応じて今でも利用します。
for k = 1:length(x)
addpoints(h,x(k),y(k)); % ループでデータを追加
drawnow % グラフアップデート
frame = getframe(gcf); % Figure 画面をムービーフレーム(構造体)としてキャプチャ
tmp = frame2im(frame); % 画像に変更
[A,map] = rgb2ind(tmp,256); % RGB -> インデックス画像に
if k == 1 % 新規 gif ファイル作成
imwrite(A,map,filename,'gif','LoopCount',Inf,'DelayTime',0.2);
else % 以降、画像をアペンド
imwrite(A,map,filename,'gif','WriteMode','append','DelayTime',0.2);
end
end
これからは生成AIでコードを1から書くという事が減ってくるのかと思いますが,皆さんがMATLABのコードを書く時に意識しているご自身のルールのようなものがあれば教えてください.
MATLAB言語は柔軟に書けますが,自然と個人個人のルールというものが出来上がってきているのでは,と思います.
私はParameter, Valueペアの引数がある関数はそれぞれのペアを新しい行に書く,というのをよくやります.
h = plot(x, y, "ro-", ...
"LineWidth", 2, ...
"MarkerSize", 10, ...
"MarkerFaceColor", "g");
Parameter=Valueでも同じです.
h = plot(x, y, "ro-", ...
LineWidth = 2, ...
MarkerSize = 10, ...
MarkerFaceColor = "g");
また,一時期は "=" を揃えることもやってました(今はやってませんが).
h = plot(x, y, "ro-", ...
LineWidth = 2, ...
MarkerSize = 10, ...
MarkerFaceColor = "g");
皆さんにはどのようなルールがありますか?
先日も X にポストしましたが、これ Ctrl + A, Ctrl + I
コードを書き加えながら定期的に手癖で Ctrl + A, Ctrl + I。for ループ書き直しているときなどインデント乱れがちですのでよく使います。
「これは、昨日知りたかったやつ。。便利!」(X
「めっちゃ使ってるこれ会社の人に教えたら「今までスペースキーで頑張ってたのはいったい…」て膝から崩れ落ちるような感じになってた」(X
そんな声がありました。
普段使っているショートカットキーも他の人にとっては未知なものかも。ここで共有してコード書きの効率あげていきましょう!
michio
michio
Ultima attività il 2 Giu 2025

昨日 5/29 にお台場で MATLAB EXPO が開催されました。ご参加くださった方々ありがとうございました!
私は AI 関連のデモ展示で解説員としても立っておりましたが、立ち寄ってくださる方が絶えず、ずっと喋り続けてました。また、講演後に「さっきのすごくね?」という会話が漏れ聞こえてきたのがハイライト。
参加されたみなさま、印象に残ったこと・気になった講演・ポスター・デモ・新機能等あったら教えてください!(次回に向けて運営面での感想も)
以前のEXPOでも参加・聴講したことがある
67%
知り合いから聞いた
0%
MathWorksからのプロモーション,EXPOサイトで知った
0%
今年のEXPO会場でたまたま見かけた
0%
ライトニングトークって何?
33%
3 voti