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Zhaoxu Liu / slandarer
Last activity 3 分钟前

Christmas Tree for Matlaber : Rotating With Falling Snowflakes

Christmas is coming, here are two dynamic Christmas tree drawing codes:

Crystal XMas Tree

function XmasTree2024_1
fig = figure('Units','normalized', 'Position',[.1,.1,.5,.8],...
    'Color',[0,9,33]/255, 'UserData',40 + [60,65,75,72,0,59,64,57,74,0,63,59,57,0,1,6,45,75,61,74,28,57,76,57,1,1]);
axes('Parent',fig, 'Position',[0,-1/6,1,1+1/3], 'UserData',97 + [18,11,0,13,3,0,17,4,17],...
      'XLim',[-1.5,1.5], 'YLim',[-1.5,1.5], 'ZLim',[-.2,3.8], 'DataAspectRatio', [1,1,1], 'NextPlot','add',...
      'Projection','perspective', 'Color',[0,9,33]/255, 'XColor','none', 'YColor','none', 'ZColor','none')
%% Draw Christmas tree
F = [1,3,4;1,4,5;1,5,6;1,6,3;...
    2,3,4;2,4,5;2,5,6;2,6,3];
dP = @(V) patch('Faces',F, 'Vertices',V, 'FaceColor',[0 71 177]./255,...
    'FaceAlpha',rand(1).*0.2+0.1, 'EdgeColor',[0 71 177]./255.*0.8,...
    'EdgeAlpha',0.6, 'LineWidth',0.5, 'EdgeLighting','gouraud', 'SpecularStrength',0.3);
r = .1; h = .8; 
V0 = [0,0,0; 0,0,1; 0,r,h; r,0,h; 0,-r,h; -r,0,h];
% Rotation matrix
Rx = @(V, theta) V*[1 0 0; 0 cos(theta) sin(theta); 0 -sin(theta) cos(theta)];
Rz = @(V, theta) V*[cos(theta) sin(theta) 0;-sin(theta) cos(theta) 0; 0 0 1];
N = 180; Vn = zeros(N, 3); eval(char(fig.UserData))
for i = 1:N
    tV = Rz(Rx(V0.*(1.2 - .8.*i./N + rand(1).*.1./i^(1/5)), pi/3.*(1 - .6.*i./N)), i.*pi/8.1 + .001.*i.^2) + [0,0,.016.*i];
    dP(tV); Vn(i,:) = tV(2,:);
end
scatter3(Vn(:,1).*1.02,Vn(:,2).*1.02,Vn(:,3).*1.01, 30, 'w', 'Marker','*', 'MarkerEdgeAlpha',.5)
%% Draw Star of Bethlehem
w = .3; R = .62; r = .4; T = (1/8:1/8:(2 - 1/8)).'.*pi;
V8 = [ 0, 0, w;  0, 0,-w;
       1, 0, 0;  0, 1, 0; -1, 0, 0;  0,-1,0;
       R, R, 0; -R, R, 0; -R,-R, 0;  R,-R,0;
       cos(T).*r, sin(T).*r, T.*0];
F8 = [1,3,25; 1,3,11; 2,3,25; 2,3,11; 1,7,11; 1,7,13; 2,7,11; 2,7,13;
      1,4,13; 1,4,15; 2,4,13; 2,4,15; 1,8,15; 1,8,17; 2,8,15; 2,8,17;
      1,5,17; 1,5,19; 2,5,17; 2,5,19; 1,9,19; 1,9,21; 2,9,19; 2,9,21;
      1,6,21; 1,6,23; 2,6,21; 2,6,23; 1,10,23; 1,10,25; 2,10,23; 2,10,25];
V8 = Rx(V8.*.3, pi/2) + [0,0,3.5];
patch('Faces',F8, 'Vertices',V8, 'FaceColor',[255,223,153]./255,...
      'EdgeColor',[255,223,153]./255, 'FaceAlpha', .2)
%% Draw snow
sXYZ = rand(200,3).*[4,4,5] - [2,2,0];
sHdl1 = plot3(sXYZ(1:90,1),sXYZ(1:90,2),sXYZ(1:90,3), '*', 'Color',[.8,.8,.8]);
sHdl2 = plot3(sXYZ(91:200,1),sXYZ(91:200,2),sXYZ(91:200,3), '.', 'Color',[.6,.6,.6]);
annotation(fig,'textbox',[0,.05,1,.09], 'Color',[1 1 1], 'String','Merry Christmas Matlaber',...
    'HorizontalAlignment','center', 'FontWeight','bold', 'FontSize',48,...
    'FontName','Times New Roman', 'FontAngle','italic', 'FitBoxToText','off','EdgeColor','none');
% Rotate the Christmas tree and let the snow fall
for i=1:1e8
    sXYZ(:,3) = sXYZ(:,3) - [.05.*ones(90,1); .06.*ones(110,1)];
    sXYZ(sXYZ(:,3)<0, 3) = sXYZ(sXYZ(:,3) < 0, 3) + 5;
    sHdl1.ZData = sXYZ(1:90,3); sHdl2.ZData = sXYZ(91:200,3);
    view([i,30]); drawnow; pause(.05)
end
end

Curved XMas Tree

function XmasTree2024_2
fig = figure('Units','normalized', 'Position',[.1,.1,.5,.8],...
    'Color',[0,9,33]/255, 'UserData',40 + [60,65,75,72,0,59,64,57,74,0,63,59,57,0,1,6,45,75,61,74,28,57,76,57,1,1]);
axes('Parent',fig, 'Position',[0,-1/6,1,1+1/3], 'UserData',97 + [18,11,0,13,3,0,17,4,17],...
      'XLim',[-6,6], 'YLim',[-6,6], 'ZLim',[-16, 1], 'DataAspectRatio', [1,1,1], 'NextPlot','add',...
      'Projection','perspective', 'Color',[0,9,33]/255, 'XColor','none', 'YColor','none', 'ZColor','none')
%% Draw Christmas tree
[X,T] = meshgrid(.4:.1:1, 0:pi/50:2*pi);
XM = 1 + sin(8.*T).*.05;
X = X.*XM; R = X.^(3).*(.5 + sin(8.*T).*.02);
dF = @(R, T, X) surf(R.*cos(T), R.*sin(T), -X, 'EdgeColor',[20,107,58]./255,...
    'FaceColor', [20,107,58]./255, 'FaceAlpha',.2, 'LineWidth',1);
CList = [254,103,110; 255,191,115; 57,120,164]./255;
for i = 1:5
    tR = R.*(2 + i); tT = T+i; tX = X.*(2 + i) + i;
    SFHdl = dF(tR, tT, tX);
    [~, ind] = sort(SFHdl.ZData(:)); ind = ind(1:8);
    C = CList(randi([1,size(CList,1)], [8,1]), :);
    scatter3(tR(ind).*cos(tT(ind)), tR(ind).*sin(tT(ind)), -tX(ind), 120, 'filled',...
        'CData', C, 'MarkerEdgeColor','none', 'MarkerFaceAlpha',.3)
    scatter3(tR(ind).*cos(tT(ind)), tR(ind).*sin(tT(ind)), -tX(ind), 60, 'filled', 'CData', C)
end
%% Draw Star of Bethlehem
Rx = @(V, theta) V*[1 0 0; 0 cos(theta) sin(theta); 0 -sin(theta) cos(theta)];
% Rz = @(V, theta) V*[cos(theta) sin(theta) 0;-sin(theta) cos(theta) 0; 0 0 1];
w = .3; R = .62; r = .4; T = (1/8:1/8:(2 - 1/8)).'.*pi;
V8 = [ 0, 0, w;  0, 0,-w;
       1, 0, 0;  0, 1, 0; -1, 0, 0;  0,-1,0;
       R, R, 0; -R, R, 0; -R,-R, 0;  R,-R,0;
       cos(T).*r, sin(T).*r, T.*0];
F8 = [1,3,25; 1,3,11; 2,3,25; 2,3,11; 1,7,11; 1,7,13; 2,7,11; 2,7,13;
      1,4,13; 1,4,15; 2,4,13; 2,4,15; 1,8,15; 1,8,17; 2,8,15; 2,8,17;
      1,5,17; 1,5,19; 2,5,17; 2,5,19; 1,9,19; 1,9,21; 2,9,19; 2,9,21;
      1,6,21; 1,6,23; 2,6,21; 2,6,23; 1,10,23; 1,10,25; 2,10,23; 2,10,25];
V8 = Rx(V8.*.8, pi/2) + [0,0,-1.3];
patch('Faces',F8, 'Vertices',V8, 'FaceColor',[255,223,153]./255,...
      'EdgeColor',[255,223,153]./255, 'FaceAlpha', .2)
annotation(fig,'textbox',[0,.05,1,.09], 'Color',[1 1 1], 'String','Merry Christmas Matlaber',...
    'HorizontalAlignment','center', 'FontWeight','bold', 'FontSize',48,...
    'FontName','Times New Roman', 'FontAngle','italic', 'FitBoxToText','off','EdgeColor','none');
%% Draw snow
sXYZ = rand(200,3).*[12,12,17] - [6,6,16];
sHdl1 = plot3(sXYZ(1:90,1),sXYZ(1:90,2),sXYZ(1:90,3), '*', 'Color',[.8,.8,.8]);
sHdl2 = plot3(sXYZ(91:200,1),sXYZ(91:200,2),sXYZ(91:200,3), '.', 'Color',[.6,.6,.6]);
for i=1:1e8
    sXYZ(:,3) = sXYZ(:,3) - [.1.*ones(90,1); .12.*ones(110,1)];
    sXYZ(sXYZ(:,3)<-16, 3) = sXYZ(sXYZ(:,3) < -16, 3) + 17.5;
    sHdl1.ZData = sXYZ(1:90,3); sHdl2.ZData = sXYZ(91:200,3);
    view([i,30]); drawnow; pause(.05)
end
end

I wish all MATLABers a Merry Christmas in advance!

Steve Eddins
Last activity 2024-12-12，21:25

It's time to retire and replace IMSHOW

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.

Paul
Last activity 大约 3 小时前

Would a General Hold/Release Functionality be a Good Feature for the Symbolic Toolbox?

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 =

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.

Off Topic

Audace NSHIMIRIMANA
Last activity 2024-12-10，23:34

Improvement of Energy Management Strategy (EMS) of Plug In Hybrid Electric Vehicles (PHEV) Using Rule-based Control Strategy and Signal Processing / ITS

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

David
Last activity 2024-12-9，20:01

MATLAB Answers Maintenance Today @1PM

We will be updating the MATLAB Answers infrastructure at 1PM EST today. We do not expect any disruption of service during this time. However, if you notice any issues, please be patient and try again later. Thank you for your understanding.

https://blogs.mathworks.com/loren/2016/04/01/the-queens-matlab/?s_tid=srchtitle_site_search_4_rgb2gray

Image Analyst
Last activity 2024-12-5，5:43

Difference between gray and grey

To convert a color image to grayscale, use rgb2gray, or is it rgb2grey?

(1) Ben Hayden: "When you are using matlab and you want to get the square root of the result of the most recent command line operation." — Bluesky

Mike Croucher
Last activity 2024-12-2，23:15

An unintentional MATLAB meme

I enjoyed this post on BlueSky yesterday

Image Analyst
Last activity 2024-12-2，22:14

MATLAB Ornament

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.)

Generative AI

Frédéric Dorschner
Last activity 2024-11-22，13:04

Colors to differenciate input, output and intermediate signals

Is it possible to differenciate the input, output and in-between wires by colors?

@Dhimas Mahardika / Creating Butterflies using Mathematics Formula

Chen Lin
Last activity 2024-12-7，7:25

MathWorks Merch Shop Is Open

Hello, MATLAB fans!

For years, many of you have expressed interest in getting your hands on some cool MathWorks merchandise. I'm thrilled to announce that the wait is over—the MathWorks Merch Shop is officially open!

In our shop, you'll find a variety of exciting items, including baseball caps, mugs, T-shirts, and YETI bottles.

Visit the shop today and explore all the fantastic merchandise we have to offer. Happy shopping!

Generative AI

Bob Gastineau
Last activity 2024-12-4，1:12

AI Chat playground accuracy metrics

I was curious to startup your new AI Chat playground.

The first screen that popped up made the statement:

"Please keep in mind that AI sometimes writes code and text that seems accurate, but isnt"

Can someone elaborate on what exactly this means with respect to your AI Chat playground integration with the Matlab tools?

Are there any accuracy metrics for this integration?

Contests

Chen Lin
Last activity 2024-11-15

MATLAB Shorts Contest - Grand Prize Winners Announced!

We are thrilled to announce the grand prize winners of our MATLAB Shorts Mini Hack contest! This year, we invited the MATLAB Graphics and Charting team, the authors of the MATLAB functions used in every entry, to be our judges. After careful consideration, they have selected the top three winners:

1st place - Tim

Judge comments: Realism & detailed comments; wowed us with Manta Ray

2nd place – Jenny Bosten

Judge comments: Topical hacks : Auroras & Wind turbine; beautiful landscapes & nightscapes

3rd place - Vasilis Bellos

Judge comments: Nice algorithms & extra comments; can’t go wrong with Pumpkins

There is also an Honorable Mention - William Dean

Judge comments: Impressive spring & cubes!

In addition, after validating the votes, we are pleased to announce the top 10 participants on the leaderboard:

@Tim / Manta Ray

@Safin / Happy Shaping!!!

@Kaustubh / Fourier Circle Art

@William Dean / Trefoil Spring

@Malik / Moonlit Night

@Sonesson / Rubix Cube

@Zhaoxu Liu / slandarer / Dragon in the deep sea

@Jenny Bosten / Lake view to the North

@Matteo / Trapped particles++

Congratulations to all! Your creativity and skills have inspired many of us to explore and learn new skills, and make this contest a big success!

Hans Scharler
Last activity 2024-11-11

[cross posted] List of niche features you want in generic Matlab

Reddit Link: https://www.reddit.com/r/matlab/comments/1gojfod/list_of_niche_features_you_want_in_generic_matlab/

Contests

Chen Lin
Last activity 2024-11-6

An interview with Jenny Bosten

Dear MATLAB contest enthusiasts,

Welcome to the third installment of our interview series with top contest participants! This time we had the pleasure of talking to our all-time rock star – @Jenny Bosten. Every one of her entries is a masterpiece, demonstrating a deep understanding of the relationship between mathematics and aesthetics. Even Cleve Moler, the original author of MATLAB, is impressed and wrote in his blog: "Her code for Time Lapse of Lake View to the West shows she is also a wizard of coordinate systems and color maps."

The interview has been published on the MATLAB Community Blog. We highly encourage

you to read it to learn more about Jenny’s journey, her creative process, and her favorite entries.

Question: Who would you like to see featured in our next interview? Let us know your thoughts in the comments!

Matteo / Trapped particles++

Image Analyst
Last activity 2024-11-7

Shade between curves

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?

Contests

Chen Lin
Last activity 2024-11-7

Week 4 Winners Announced! Final Week to Vote on Entries

Over the past 4 weeks, 250+ creative short movies have been crafted. We had a lot of fun and, more importantly, learned new skills from each other! Now it’s time to announce week 4 winners.

Nature:

Malik / Moonlit Night

Jenny Bosten / Lake view to the North

Timothy / Refraction

Teodo / Whispers of the Ocean's Breeze

3D:

Vasilis Bellos / Ripples 3D

William Dean / Trefoil Spring

Seamless loop:

博正 / Hue phase loop complex function graph

Holiday:

Michael C. / Pumpkin Pixels

Fractal:

Greg Hungerford / Distorted Newton's Method Fractal IV

Congratulations! Each of you won your choice of a T-shirt, a hat, or a coffee mug. We will contact you after the contest ends.

Weekly Special Prizes

Sonesson / My Short Rubix Adventure

Teodo / MATLAB's Fractal Art

Vasilis Bellos / Masking 3D Surfaces and Carving Pumpkins - A Halloween Special!

Thank you for sharing your tips & tricks with the community. These great technical articles will benefit community users for many years. You won a limited-edition pair of MATLAB Shorts!

In week 5, let’s take a moment to sit back, explore all of the interesting entries, and cast your votes. Reflect what you have learned or which entries you like most. Share anything in our Discussions area! There is still time to win our limited-edition MATLAB Shorts.

cui,xingxing
Last activity 2024-12-11，1:04

MATLAB is looking forward to having an intelligent AI programming assistant similar to GitHub Copilot

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.

Chen Lin
Last activity 2024-11-10

Vote on MATLAB Short Movies and win MATLAB T-shirts Before Nov. 10th!

What incredible short movies can be crafted with no more than 2000 characters of MATLAB code? Discover the creativity in our GALLERY from the MATLAB Shorts Mini Hack contest.

Vote on your favorite short movies by Nov.10th. We are giving out MATLAB T-shirts to 10 lucky voters!

Tips: the more you vote, the higher your chance to win.

Chen Lin
Last activity 2024-11-1

Experience Insight and Innovation with Keynote Speaker, María Elena Gavilán Alfonso!

Mark your calendar for November 13–14 and get ready for two days of learning, inspiration, and connections!

We are thrilled to announce that MathWork’s incredible María Elena Gavilán Alfonso was selected as a keynote speaker at this year’s MATLAB Expo.

Her session, "From Embedded to Empowered: The Rise of Software-Defined Products," promises to be a game-changer! With her expertise and insights, María is set to inspire and elevate our understanding of the evolving world of software-defined products.

Watch a sneak peek here and get a taste of what's to come!

Interested in attending? Sign up at matlabexpo.com/online

matlab expo