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Mayla
Mayla
Last activity 2023 年 9 月 13 日

Problem 2022. Find a Pythagorean triple

That's the question: Given four different positive numbers, a, b, c and d, provided in increasing order: a < b < c < d, find if any three of them comprise sides of a right-angled triangle. Return true if they do, otherwise return false .
I wrote this code but it doesn't pass test 7. I don't really understand why it isn't working. Can somebody help me?
function flag = isTherePythagoreanTriple(a, b, c, d)
a2=a^2
b2=b^2
c2=c^2
d2=d^2
format shortG
if a2+b2==c2
flag=true
else if a2+b2==d2
flag=true
else if a2+c2==d2
flag=true
else if c2+b2==d2
flag=true
else flag=false
end
end
end
end
end
Mayla
Mayla
Last activity 2023 年 10 月 24 日

Problem 44952. Find MPG of Lightest Cars

That's the question:
The file cars.mat contains a table named cars with variables Model, MPG, Horsepower, Weight, and Acceleration for several classic cars.
Load the MAT-file. Given an integer N, calculate the output variable mpg.
Output mpg should contain the MPG of the top N lightest cars (by Weight) in a column vector.
I wrote this code and the resulting column vector has the right values but it doesn't pass the tests. What's wrong?
function mpg = sort_cars(N)
load cars.mat
sorted=sortrows(cars,4)
mpg = sorted(1:N,2)
end
I recently have found that I am no longer able to give my difficulty rating for questions on Cody after sucessfully completing a question. This is obviously not a big deal, I was just wondering if this was an issue on my end or if there was some change that I was not aware of.
The option to rate does not pop up after solving a problem, and the rating in general does not even show up anymore when answering questions (though it is visible from problem groups).
When solving problems over on Cody, I can almost always view all solutions to a problem after submitting a correct solution of my own. Very rarely, however, this is not the case, and I instead get the following message:
This solution is locked. To view this solution, you need to provide a solution of the same size or smaller.
You may solve another problem from Community group to unlock all the solutions to this problem.
If this happens, then again, I can almost always rectify this by submitting a (correct) solution to a different problem (I take it that the Community group is the implicit group of all problems on Cody --- is it?). But sometimes that, too, fails.
So my question is, why? What are the criteria that determine when all solutions are, in fact, unlocked?
(There is a related question here, but I feel the posted answer does not answer the question.)
Simple question: I noticed there's a Modeling & Simulation Challenge Master badge over on Cody, but I can't find the corresponding group. So: where is it? Does it still exist at all?
Error: The server timed out while running and assessing your solution in MATLAB CODY. How do I resolve this? My code is correct. I have run it on PC. But, when i submit in CODY the server throws an error.
Chen Lin
Chen Lin
Last activity 2022 年 11 月 11 日

3 things to do after community contests 2022

4 weeks of contests is fun but intense. Next, we recommend 3 things to do as warm-down exercises.
1. Complete 1-minute contest survey
To make future contests better and more appealing to you, we created a 1-minute survey to understand your experience. Your feedback is critical to us!
2. Read 2022 Mini Hack Content Analysis blog post by Dave Bulkin
Dave Bulkin is a developer on the MATLAB Graphics and Charting Team. In the Blog post, @Dave B not only examines the code behind the leading entries, but also introduces you to some new visualization techniques.
3. Solve The Cody First XI – MATLAB Problems for Cricket Fans by Matt Tearle
Matt Tearle is from MathWorks Training Services Team. @Matt Tearle created this problem group to celebrate the 10th anniversary of Cody and the 2022 T20 World Cup (which happened to occur at the same time). Note that the problems can be done without the knowledge of cricket.
Thank you in advance and hope to see you in 2023!
I've now seen linear programming questions pop up on Answers recently, with some common failure modes for linprog that people seem not to understand.
One basic failure mode is an infeasible problem. What does this mean, and can it be resolved?
The most common failure mode seems to be a unbounded problem. What does this mean? How can it be avoided/solved/fixed? Is there some direction I can move where the objective obviously grows without bounds towards +/- inf?
Finally, I also see questions where someone wants the tool to produce all possible solutions.
A truly good exposition about linear programming would probably result in a complete course on the subject, and Aswers is limited in how much I can write (plus I'll only have a finite amount of energy to keep writing.) I'll try to answer each sub-question as separate answers, but if someone else would like to offer their own take, feel free to do so as an answer, since it has been many years for me since I learned linear programming.
The 2022 community contests have concluded! During the 4 weeks, we hope you had a lot of fun and learned some MATLAB skills. Together, we've achieved amazing milestones:
  • 500+ entries and 5,000+ votes created in the Mini Hack 2022 contest.
  • 100,000+ solutions submitted in Cody 10th Anniversary contest
  • 2,000+ participants in both contests
Now, it's time to announce weekly winners and grand prize winners!
Mini Hack - Pick of the MATLAB Graphics Team
We invited the MATLAB Graphics team, the authors of the MATLAB functions used in every entry, to be our Mini Hack judges. Here are their picks in 3 categories:
  • Our Top 3:
Rising Hand by Augusto Mazzei
Object used: fill; Judge comments: Clever code, nice metaphor, kind comments
Above the clouds by Tim
Object used: patch (via VOXview); Judge comments: Very pretty, looks like it could be in a video game
Monocular rivalry by Jenny Bosten
Object used: Image; Judge comments: We spent a too much time trying to figure out what this illusion was doing to our brains
  • Clever use of Charts:
Holiday Festivities at MATropolis! by Anton Kogios
Object used: Bar3; Judge comments: Cute! Nice fireworks!
Ship by Shanshan Wang
Object used: histogram2; Judge comments: We didn't realize there was a ship in the flow data set
A fish for fun by Shanshan Wang
Object used: plot; Judge comments: Nifty and very different from other entries.
Colorful Fibonacci Spiral #3 by Basil Imoberdorf
Object used: scatter; Judge comments: Overlapping markers make for a very cool tunnel-like effect
  • Things we still loved:
Sandstone by Tim
Object used: image; Judge comments: Domain Warping FTW
Jellyfish by Tim
Object used: surface; Judge comments: Clever use of transparency
Congratulations and you should be very proud of yourself! It's a huge achievement that your entry is recognized by the MATLAB Graphics team!
Mini Hack - special category for Week 4
Our Week 4 special category is ‘Holiday’. The winner is Christmas snowman by Simon Thor
Mini Hack - grand prize winners
After an intensive (and very time-consuming) review of votes on winning entries, we have finalized the list of grand prize winners. Huge congratulations! We appreciate the time and effort you spent and the awesome entries you created. Each of you won an Amazon gift card.
Anton Kogios, Brandon Caasenbrood, KARUPPASAMYPANDIYAN M, Teodo, Jenny Bosten, MvLevi, Abdullah Caliskan, Stewart Thomas, Jonas Schlatter, and Tim Davis
Cody 10th Anniversary - surprise prize for 28-day streak winners
We are thrilled to see that 37 players have built a streak of 28 days! Coming back every day to solve problems is an incredible achievement. We decided to show our appreciation by awarding a surprise prize to those 37 players. Congratulations! Each of you will get a MathWorks T-shirt.
Christian Schröder, Stefan Abendroth, Mohammed, Victoria, Vasileios Pasialis, Gerardo Domínguez Ramírez, HH, Anton Kogios, Lizhi Zhu, Marco Fuscà, Armando Longobardi, Monica, Rithik KRT, Ayman, Teodo, Lincoln Poon, Elijah Keifert, siranjeevi gurumani, kazuyoshi kouno, Ryan Koh, Manuela Kaiser, Mehmet OZC, Dyuman Joshi, KOTHAPALLI SRI BRINDA, Gergely Patay, abyss, Takumi, Keita Abe, Petr Cerny, Shubham Shubham, Meredith, Andrew K, Atsushi Ueno, Peter Orthmann, Armando Longobardi, Chuang Tao, and David Romero
Cody 10th Anniversary winners – Week 4
The top 3 players for solving the most problems in week 4 are Christian Schröder, Gerardo Dominguez Ramirez, and Stefan Abendroth, Congratulations! Each of you won an Amazon gift card.
Week 4 lucky winners are Qingrui Liu and Basant Ale.
Cody 10th Anniversary winners – grand prize winners
We know how hard it is to be a top-10 leader in the contest leaderboard! It requires a huge time commitment and advanced MATLAB skills. Congratulations! Each of you will win an Amazon gift card.
Christian Schröder, Stefan Abendroth, Mohammed, Victoria, Vasileios Pasialis, Gerardo Domínguez Ramírez, HH, Anton Kogios, Lizhi Zhu, and Marco Fuscà
Lucky voters and participants
Thank you for your participation in our 2022 contests. You don’t need to be on the top of the leaderboards to win. As we announced, we would give out 20 MathWorks T-shirts to lucky voters and participants of the 2 contests.
Ismail Bera Altan, Robin Stolz, Michael Mellin, Kellan Smith, Neha Shaah, Siranjeevi gurumani, Paul Villain, Andrew Horchler, Meg Noah, Saurabh Chaudhary, Pakize erdogmus, Godfrey Ojerheghan, Selena Mastrodonato, Damir Rasic, Thomas Kjeldsen, Meredith, John Noah Ramiterre, Patience Oliveira, Panda, and Sujeet Kumar Choudhary
On behalf of the MATLAB Central community team, we thank you for joining our celebration of the MATLAB Central community 2022 contests. We hope you enjoyed these contests and look forward to seeing you in next year’s contests.
In Week 3, several new milestones have been achieved! Cody 10th contest has reached the 80,000-solution milestone! Mini Hack has over 400 entries. @Tim Davis’ seashell entry actually inspired a MathWorks blog post. Check it out.
During the last week of this contest, we strongly encourage you to inspire your colleagues, classmates, or friends to vote. Let the world know the beauty of Mathematics. Voters will also have the opportunity to win a MATLAB T-shirt.
MATLAB Mini Hack Winners - Week 3
In week 2, we announced the special category for week 3 is nature. Below are the 3 winners for this category.
Winners of other categories are:
Congratulations! Each of you won a T-shirt. I just heard we have 4 designs of MATLAB T-shirts. Can you collect all of them?
Cody 10th Anniversary Winners - Week 3
  • The top 3 players for solving the most problems in week 3 are Christian Schröder, Marco Fuscà, and Stefan Abendroth, Congratulations! Each of you won an Amazon gift card.
  • As long as you participate, you have the opportunity to win MathWorks T-shirts. Week 3 lucky winners are Luffy Wangand Augusto Mazzei.
What’s new in week 4?
MATLAB Mini Hack 2022:
  • Week 4’s new category is holiday! Halloween is around the corner. What holidays are you celebrating?
  • You are able to leverage Signal Processing Toolbox in your entry.
Cody 10th Anniversary:
Chen Lin
Chen Lin
Last activity 2023 年 1 月 24 日

We ordered too many T-shirts! Want one?

Want a MATLAB T-shirt? We have 10 more to give out in the 10 days between now and Oct. 30th. You might win a MATLAB T-shirt by doing any of these activities:
  • Vote on entries you like from the Mini Hack contest
  • Solve Cody problems in the Cody 10th contest
  • Create or remix entries in the Mini Hack contest
The more activities you do, the higher your chance to win. Every day, we will pick a winner.
We had another wonderful week of community contests 2022. In week 2, the voting for Mini Hack started! About 1000 votes have been cast on 300+ entries. In Cody 10th Anniversary contest, we already have 85 finishers for the two special groups: Matrices and Arrays and Plotting and Visualization.
Now, it’s time to announce the weekly winners!
MATLAB Mini Hack Winners - Week 2
Amazing entries keep coming in every day. In week 2, we announced a space category to celebrate the milestone of NASA’s Dart mission. We’ve picked 4 winners for this new category.
Winners of other categories are:
Congratulations! Each of you won a MathWorks T-shirt. If this is the second time you won, you have the option to choose a MathWorks hat or a coffee mug!
Cody 10th Anniversary Winners - Week 2
  • The top 3 players for solving most problems in week 2 are Mohammed, Armando Longobardi, and Stefan Abendroth, Congratulations! Each of you won an Amazon gift card.
  • You don’t need to be an expert or spend tons of time to win! As long as you participate, you have the opportunity to win MathWorks T-shirts. Week 2 lucky winners are Dylan Baker and Takumi.
What’s new in week 3?
MATLAB Mini Hack 2022:
  • Week 3’s new category is nature! We look forward to seeing more nature-themed creative entries from you!
  • You are able to leverage up to 2 File Exchange submissions in your code.
Cody 10th Anniversary:
You might have read the news that NASA successfully crashed a spacecraft into an asteroid to alter the asteroid’s course. But did you know the spacecraft’s autonomous guidance system was developed in MATLAB and C++? Check out our latest blog post to learn more details.
Let’s celebrate this scientific milestone by creating astronomy-themed entries in the Mini Hack contest. Be creative and leverage the existing submissions in File Exchange. We will award special prizes to the best entries.
Just in one week, 200 amazing images were created in the Mini Hack contest and 20,000 solutions were submitted in the Cody contest. What an amazing week! Time to announce the winners.
MATLAB Mini Hack Winners - Week 1
Your awesome work made our judging VERY HARD! We came up with several categories for winning entries. Congratulations to the winners! Each of you won a MathWorks T-shirt:
Cody 10th Anniversary Winners - Week 1
  • The top 3 players for solving most problems in week 1 are Mohammed, Stefan Abendroth, and Hans Bourgeois. Congratulations! Each of you won an Amazon gift card.
  • You don’t need to be an expert or spend tons of time to win! As long as you participate, you have the opportunity to win MathWorks T-shirts. Week 1 lucky winners are Meredith Reid and KARUPPASAMYPANDIYAN M.
In Week 2, we’ve added more fun to the contests!
MATLAB Mini Hack 2022:
  • Voting started. Cast your votes on your favorite images. Help us show the world the beauty of mathematics by sharing your work with your friends, classmates, or colleagues.
  • Toolboxes unlocked. You are able to leverage the Image Processing Toolbox to generate even more interesting images. We will award the best entries leveraging the Image Processing Toolbox.
Cody 10th Anniversary:
The contest development team has identified an issue when trying to link your new entries to submissions in the File Exchange. The issue has prevented some users from successfully linking their entries. We have a fix and will be deploying it today at 3pm EST.
Two fun community contests: MATLAB Mini Hack 2022 and Cody 10th Anniversary start today on Oct. 3rd!
Participants across all skill levels are welcome to join! Even if you have limited time, you still have opportunities to win as long as you participate.
Want to challenge yourself and win Amazon gift Cards and limited-edition Badges?
1. MATLAB Mini Hack 2022: Create your best entry (either a new or a remixed entry).
2. Cody 10th Anniversary: Solve your 1st Cody problem today!
If you have any questions about the contest rules or prizes, let us know by replying to this thread.
We hope you enjoy the contests, improve your MATLAB skills, and win prizes! Now, let the party begin!
Just in case, I have my license of MATLAB. I just have this question and I didn't find any information. I wouldn't like to create another account, for this reason I prefer to ask here.
Chen Lin
Chen Lin
Last activity 2022 年 10 月 8 日

5 Days Until Community Contests Begin. Get Ready!

Two fun community contests: MATLAB Mini Hack 2022 and Cody 10th Anniversary will start on Oct 3rd, 2022. Are you ready for the challenges and big prizes?
How to Play
1. MATLAB Mini Hack 2022 contest:
Use up to 280 characters of MATLAB code to generate an interesting image. New in 2022 contest: You'll be allowed to use functions from File Exchange entries and/or certain MathWorks toolboxes in different weeks.
2. Cody 10th Anniversary contest:
Solve at least 1 Cody problem per day during the 4-week contest period. We will reward participants with the longest streak of days of problem-solving!
Tips to Win
1. MATLAB Mini Hack 2022: Spend time creating your best work (either a new or remixed entry).
2. Cody 10th Anniversary: Make sure you start on the 1st day (Oct 3rd). This is the key if you want to win one of the grand prizes (worth marking your calendar?)
3. Act now: No matter if you want to join either the Mini Hack, Cody, or both. Start planning your strategy today.
Good luck! We hope you are the winner.
I have submitted a problem in cody some days back. Now it is not showing in my profile. Initially it was accepted and some people submitted the solutions also, however It has been removed after that, are there some guidelines which I am not following?
Hi everyone
I am a new of this community and I very interested in this forum and Matlab.I am trying to submit a soultion but as tiltle my code has a built-in function so the test systerm dont reconisie it.It run completely ok on my computer.
This is problem
https://www.mathworks.com/matlabcentral/cody/problems/45196-determine-whether-a-given-point-is-inside-or-outside-a-polygon/solutions/new
This is my solution
function [boOut] = BoIfPointInPoly(PolyMatrix,p_test)
%Summary of this function goes here
%{
if we draw a line from test point to a central point of a side of The polygon
then we extend that line to the furthest point of the polygon ensure that
line go through all side of Polygon in 1 direction.I call that line is line_test
Next find number of intersert of line test and all sides w polyxpoly
function
num interset point is odd mean p_test inside
num interset point is even mean p_test outside
this solution go from the concept that if a line go in from a side it has go out
from other side.So if it go in but not go out that mean it start from
inside.
%}
% Detailed explanation goes here
%line from p test throuh central of a side to furthest point of polygon
%find vector
V = ((PolyMatrix(1,:) + PolyMatrix(2,:)) /2) - p_test ;
%draw that vector to furtest point
pend = p_test + V * max(PolyMatrix(:));
%with multi of V and biggest element I assume that line will go all out the
%polygon which ensure out logic will right
line_test = [p_test ; pend];
disp('Our line test\n');
disp(line_test);
%find interst point
p_inter = polyxpoly(PolyMatrix(:,1),PolyMatrix(:,2),line_test(:,1),line_test(:,2));
%find number of interset (row)
[numIntere,trash] = size(p_inter);
disp('Number of interest point:');
disp(numIntere);
%determine in or out
if (rem(numIntere,2) == 0)
boOut = 0;
else
boOut = 1;
end
end
Can anyone has solution.