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Just in 2 days since the contest started, we already have 200+ awesome entries in the MATLAB Mini Hack contests. We are excited to see so many talented and creative community members enjoying the contest and learning from each other.

If you haven’t created your entry, try remixing an entry you like. Make some SMALL changes and see what it would look like. Remix is highly encouraged in this contest.

If you haven’t entered the Treasure Hunt contest, give it a try. Your participation will not only win you a prize but also bump up MathWorks’ donation to a charity organization that fights the global pandemic.

Reminder:

  • Voting will start next Monday.
  • Weekly surprise giveaways will also be announced next Monday. Still time left to create your entries, original or remixed!

As part of MATLAB Central’s 20 year anniversary celebration, we created the MATLAB Mini Hack . The contest starts today on Oct. 4th!

What to do?

Generate an interesting image using up to 280 characters of MATLAB code.

Who can play?

Participants across all skill levels are welcome. Create original entries of your own code, remix others’ entries and make them your own, or simply vote on ENTRIES you love!

How to win prizes?

Those at the top of the leaderboard at the end of the contest will win up to $300 Amazon gift cards, 5 customized T-shirts, or special badges. Visit the prizes section on the contest page for more information.

To add more fun, we will award RANDOM PRIZES that every participant has a chance to win.

  • Each week, we will pick 5 players who participate in both the Treasure Hunt and MATLAB Mini Hack .
  • Each week, we will have different surprise giveaways.

Important Notes

  • The first week (Oct. 4th, 2021 ~ Oct. 10th 2021) is for creating entries only. Voting starts on Week 2.
  • Make sure you follow the contests (click the ‘follow the contests’ button on the top) to get notified when prizes are awarded and of other important announcements. We hope you are the winner!
I need to put a number of problems on MATLAB cody under same Problem group, as many other people have done.
Can anyone please help me on this.

Join our celebration of the 20th anniversary of MATLAB Central community! You are invited to enter 2 contests - A Treasure Hunt and a MATLAB Mini Hack - to have fun and win prizes.

How to Play

  • In the Treasure Hunt, complete 10 fun tasks to explore the ‘treasures’ in the community.
  • In the MATLAB Mini Hack, use up to 280 characters of MATLAB code to generate an interesting image. Simply vote for the entries that you like or share your own entries to gain votes.

Prizes

You will have opportunities to win compelling prizes, including special edition T-shirts, customized T-shirts, Amazon gift cards, and virtual badges. Your participation will also bump up our charity donations.

Ready to participate?

Visit the community contests space and choose the contest you’d like to enter. Note that:

  • You need a MathWorks account to participate. If you don’t have a MathWorks account, you can create one at MathWorks sign in .
  • Make sure you follow the contests (click the ‘follow the contests’ button on the top) to get notified for prize information and important announcements.

For the full contest rules, prizes, and terms, see details here .

We hope you enjoy the contests and win big prizes. NOW, LET THE CELEBRATION BEGIN!

I created a problem in Cody that approximates e. To test the user's solution, I compare their solution to e. What I want to do instead is compare the user's solution to my reference solution. The question is how do I call the reference solution in the test suite?
This is currently my test suite.
sol=exp(1);
y_correct = playgame();
assessVariableEqual('y_correct',sol);
I created several problems recently in CODY. Some of them got removed automatically. I was curious as to why.
It is possible that the problems used latex in their description, so I am not sure if that was the reason they got rejected by the cody server.
Muhtasim Haque Nahian
Muhtasim Haque Nahian
上次活动时间: 2021-5-27

My problems are vanished

I created some problems last night and created a group too. All those are now missing.
Also my ranking progress, activites, badges earned last night are missing too.
Tungky Subroto
Tungky Subroto
上次活动时间: 2021-2-28

Cody challenges for Simulink ?

Hi all,
I hope everyone is doing well and keeping safe. I was wondering, are there any Cody challenges for Simulink these days?
I saw a post from 2015 (https://blogs.mathworks.com/simulink/2015/08/07/modeling-and-simulation-challenge-in-cody/) and it seems there was a Simulink or "Modeling and Simulation Challenge" problem group, but I couldn't find this group anymore. Perhaps I missing something?
Thank you beforehand.
Tungky

Happy New Year, everyone! We hope you enjoyed the Cody contest in 2020, learned new MATLAB skills, and made a friend or two. While the 2020 contest has concluded, the fun and learning never end.

Please take the 1-minute survey to talk about your experience (only 2 required questions). Our goal is to make future contests better and more appealing to you, so your feedback is critical to us.

Thank you in advance and hope to see you again in the 2021 contest.

I see this solution on the Cody solutions list. Solution 1949216
I am puzzled as to how this could possibly be rated as correct (size 48)
(BTW - I am pretty sure I saw this, or similar, before.)
function ans = fileread(varargin)
' ';
a=1;
b=3;
a=1;
b=3;a=1;
b=3;a=1;
b=3;a=1;
b=3; end
Chen Lin
Chen Lin
上次活动时间: 2020-10-1

Cody Contest 2020 Starts Today!

We are excited to announce that Cody Contest 2020 starts today! Again, the rule is simple - solve any problem and rate its difficulty. If you have any question, please visit our FAQs page first. Want to know your ranking? Check out the contest leaderboard .

Happy problem-solving! We hope you are a winner.

Chen Lin
Chen Lin
上次活动时间: 2021-1-23

Cody Contest 2020 FAQs

Below are some FAQs for the Cody contest 2020. If you have any additional questions, ask your questions by replying to this post. We will keep updating the FAQs.

Q1: If I rate a problem I solved before the contest, will I still get a raffle ticket?

A: Yes. You can rate any problem you have solved, whether it was before or during the contest period.

Q2: When will I receive the contest badges that I've earned?

A: All badges will be awarded after the contest ends.

Q3: How do I know if I’m the raffle winner?

A: If you are a winner, we will contact you to get your name and mailing address. You can find the list of winners on the Cody contest page .

Q4: When will I receive my T-shirt or hat?

A: You will typically receive your prize within a few weeks. It might take longer for international shipping.

Q5: I'm new to Cody. If I have some questions about using Cody, how can I get help?

A: You can ask your question by replying this post. Other community users might help you and we will also monitor the threads. You might also find answers here .

Q6: What do I do if I have a question about a specific problem?

A: If the problem description is unclear, the test suite is broken, or similar concerns arise, post your question(s) as a comment on the specific problem page. If you are having a hard time solving a problem, you can post a comment to your solution attempt (after submitting it). However, do not ask other people to solve problems for you.

Q7: If I find a bug or notice someone is cheating/spamming during the contest, how can I report it?

A: Use Web Site Feedback . Select "MATLAB Central" from the category list.

Q8: Why can't I rate a problem?

A: To rate a problem, you must solve that problem first and have at least 50 total points.

It's pretty odd how a solution that uses more characters than usual can be the "leading solution" of a Cody problem and have the least size. Compare these two codes that find the sum of integers from 1 to 2^x, which one uses fewer characters, thus should be the better solution?
function y = sum_int(x)
regexp '' '(?@y=sum(1:2^x);)'
end
function ans = sum_int(x)
sum(1:2^x)
end
Even
Even
上次活动时间: 2023-7-23

Problem 44951. Verify Law of Large Numbers

If a large number of fair N-sided dice are rolled, the average of the simulated rolls is likely to be close to the mean of 1,2,...N i.e. the expected value of one die. For example, the expected value of a 6-sided die is 3.5.
Given N, simulate 1e8 N-sided dice rolls by creating a vector of 1e8 uniformly distributed random integers. Return the difference between the mean of this vector and the mean of integers from 1 to N.
function dice_diff = loln(N)
A=randi([1,N],1e8,1)
M=mean(A)
B=1:N
m=mean(B)
dice_diff =abs(M-m);
end
Here is my code, but it can't work out as it needs too long time to creat A.
In problem 16 I used the following solution:
function b = nearZero(a)
b = max(a(imdilate(a == 0, [1 1 1])));
end
It is working pretty well on mathlab but when I submit my answer to cody, the following error is generated:
Undefined function 'imdilate' for input arguments of type 'double'.
Error in nearZero (line 2)
b = max(a(imdilate(a == 0, [1 1 1])));
Error in Test1 (line 3)
assert(isequal(nearZero(a),b))
In number 5, its written that the correct answer is c = 1 but the secomnd person has more change than the first person, therefor the correct answer should be 2.Likewise in number 6.
Hi, I'm trying to solve this problem but I'm getting an error so far.
Problem:
Given a vector a, find the number(s) that is/are repeated consecutively most often. For example, if you have
a = [1 2 2 2 1 3 2 1 4 5 1]
The answer would be 2, because it shows up three consecutive times
What I've written so far (not done):
a = [1 2 2 2 1 3 2 1 4 5 1];
[x,y] = size(a);
counter = zeros(1,10);
if x == 1
for i=1:1:y
if a(i) == a(i+1)
counter(a(i)) = counter(a(i))+1
end
end
else
for i=1:1:x
if a(i) == a(i+1)
counter(a(i)) = counter(a(i))+1
end
end
end
But it says "error" in the line of "if a(i) == a(i+1)". I noticed that it creates a variable called "i" which value is 11, but it should create a vector from 1 to 11. What's wrong here?
I know my solution might not be in the right direction or something, but please don't tell me anything!
Thanks in advance
Rik
Rik
上次活动时间: 2022-11-4

How to create a GUI

There are multiple ways to create a graphical user interface (GUI) in Matlab. Which method is the best depends on multiple factors: the complexity of the project, to what extent it should be a long-term solution, on what releases your GUI should work, your available time, your skill level, and probably other factors I'm forgetting.
To keep the thread clear I'll attempt to provide a short outline a few ways in this question, and leave the details for the answers. (@anyone with editing privileges: feel free to update the section below if I missed something important and am slow in editing this question)
---------------------------------------------------------------------------------------------------
GUIDE
GUIDE is probably the first tool new users will encounter. It is very useful for quickly putting something together, but it is otherwise fairly limited. It requires maintaining (and distributing) both a .m and a .fig file. Note that the GUIDE environment will be removed in a future release. After GUIDE is removed, existing GUIDE apps will continue to run in Matlab but they will not be editable in GUIDE. If you're starting a new GUI, don't use GUIDE. If you're updating an existing GUIDE GUI, migrate it to AppDesigner. In R2021a the first step for this removal was taken: all templates except the blank template have been removed.
GUILT
Although I haven't had a detailed look myself, it seems a list like this is not complete without at least mentioning the GUI Layout Toolbox, which is available on the file exchange and offers a lot of customization options.
Programmatic GUIs
You can bypass GUIDE and use the normal figures and functions like uicontrol to build GUIs from code. This makes the design less visual, but more flexible for future additions.
App Designer
The official successor to GUIDE, AppDesigner is not based on functions, but works similar to a class. It uses uifigure and mostly uses graphical elements that are incompatible with 'normal' GUIs that are created with a figure (or .fig).
Dear Sir or Madam
I tried to solve the cody-problem namend in the title.
Could you pleas tell me how I should name the vektor/variable in which it should be presentet?
Thank you for helping me.
Yours faithfully
Jann Borlinghaus
I wrote a Cody problem, but I want to prevent people from using tricks to get a false "best" solution.
For example, many people do something like the following:
regexp '' '(?@"CODE HERE)';
in order to get the size of their program down to something quite small. I want to prevent this. I have seen people using some weird tests to try to block this, but I don't know how they work and when I try to copy them they fail.