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Safin
Safin
上次活动时间: 2024-10-14

My First 'MATLAB Shorts Mini Hack 2024'

Well, this is my first time to participate in such community competitions and guess what, I've gone for 4 submissions so far (Feels Great!!)
So I wanna share some tricks that I followed for my first submission named Happy Shaping' ( Go Check it out!!):
1. Dynamic Background Color Change:
  • Technique: The background color of the figure window is gradually changed using sine and cosine functions.
  • Reason: These trigonometric functions (sin and cos) create smooth, oscillating transitions over time, which gives a fluid effect to the background's color shift.
  • Implementation:
Color = [0.1 + 0.5*abs(sin(f/10)), 0.1 + 0.5*abs(cos(f/15)), 0.9 -
0.5*abs(sin(f/20))];
  • Benefit: This introduces a smooth, visually appealing animation effect.
2. Smooth Object Motion Using Sine and Cosine:
  • Technique: The position and shape of objects are based on trigonometric functions.
  • Reason: Using sin(t) and cos(t) ensures that the movement is circular or elliptical, creating continuous and natural motion in animations.
  • Implementation (for object position):
x = 10 * cos(t * 2 * pi) * (1 + 0.5 * sin(t * pi));
y = 10 * sin(t * 2 * pi) * (1 + 0.5 * cos(t * pi));
  • Benefit: Circular and smooth motions are pleasing and easily controlled by tweaking the frequency and phase of sine/cosine functions.
3. Polygon Shape Changing Over Time:
  • Technique: The number of sides of the polygon (sides) changes dynamically based on t.
  • Reason: It creates variation in shape, maintaining user interest as the shape transitions from a triangle to a hexagon.
  • Implementation:
sides = 3 + round(3 * abs(sin(t)));
  • Benefit: This provides dynamic shape transitions over time, keeping the animation non-static.
4. Use of the fill Function for Color-Filled Shapes:
  • Technique: The fill function is used to draw a polygon with smoothly changing colors.
  • Reason: Filling polygons with varying colors based on time (t) allows for continuous color transitions, adding more complexity to the animation.
  • Implementation:
fill(xp, yp, c, 'EdgeColor', 'none');
  • Benefit: Combining both color changes and shape changes enhances the visual impact.
5. Consistent Use of hold on and hold off:
  • Technique: hold on allows multiple graphic objects to be drawn on the same axes without clearing previous objects.
  • Reason: This is crucial for drawing multiple elements (like polygons, circles, and lines) on the same figure.
  • Benefit: It helps manage and layer different graphical elements effectively within the same frame.
6. Use of rectangle for a Smooth Ball Motion:
  • Technique: The ball's motion is defined by rectangle with a Curvature of [1, 1] to make it circular.
  • Reason: Using the rectangle function simplifies the process of drawing a filled circle, and controlling its position and size is intuitive.
  • Benefit: It provides a straightforward way to animate circular objects within the plot.
7. Animating the Connection Line:
  • Technique: A white dashed line (w--) is drawn between the polygon and the moving ball to show a connection between these objects.
  • Reason: This adds interactivity to the scene, as it gives the impression that the polygon and the ball are related or connected in some way.
  • Implementation:
plot([x bx], [y by], 'w--', 'LineWidth', 2);
  • Benefit: A dynamic element that adds depth and narrative to the animation, guiding the viewer’s attention.
8. Frame Synchronization with Time (f and t):
  • Technique: The variable f is used as a frame number, while t = f / 24 creates a link between frame and time.
  • Reason: Ensuring smooth and continuous transitions in the animation over time is critical, so f acts as the control for time-based changes in shape, color, and position.
  • Benefit: This makes it easy to manage frame rates and time-based updates for the animation.
I composed 30 sound loops for use in the Mini Hack.
If you like them, please feel free to use them for free.
Try to install MATLAB2024a on Ubuntu24.04. In the image below, the button indicated by the green arrow is clickable, while the button indicated by the red arrow are unclickable, and input field where text cannot be entered, preventing the installation.
john
john
上次活动时间: 2024-10-10

Do you use MATLAB Online for teaching?

Do you use MATLAB Online for teaching? MATLAB Online lets students run MATLAB without having to install the software on the computer. All you need is a web browser and an internet connection.
I would love to hear comments and experiences of using MATLAB Online.
Let's say you have a chance to ask the MATLAB leadership team any question. What would you ask them?
saket singh
saket singh
上次活动时间: 2024-10-13

Tools Opinion

hello i found the following tools helpful to write matlab programs. copilot.microsoft.com chatgpt.com/gpts gemini.google.com and ai.meta.com. thanks a lot and best wishes.
Eric LePage
Eric LePage
上次活动时间: 2024-10-11

Paint store color swatch for Matlab

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 !
What is the side-effect of counting the number of Deep Learning Toolbox™ updates in the last 5 years? The industry has slowly stabilised and matured, so updates have slowed down in the last 1 year, and there has been no exponential growth.Is it correct to assume that? Let's see what you think!
releaseNumNames = "R"+string(2019:2024)+["a";"b"];
releaseNumNames = releaseNumNames(:);
numReleaseNotes = [10,14,27,39,38,43,53,52,55,57,46,46];
exampleNums = [nan,nan,nan,nan,nan,nan,40,24,22,31,24,38];
bar(releaseNumNames,[numReleaseNotes;exampleNums]')
legend(["#release notes","#new/update examples"],Location="northwest")
title("Number of Deep Learning Toolbox™ update items in the last 5 years")
ylabel("#release notes")
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!

How can I mechanically couple synchronous reluctance motor from simscape electrical electromechanical library and dc generator from specialized power system library

Mike Croucher
Mike Croucher
上次活动时间: 2024-9-15

Who will be at SC24?

Hot off the heels of my High Performance Computing experience in the Czech republic, I've just booked my flights to Atlanta for this year's supercomputing conference at SC24.
Will any of you be there?
John D'Errico
John D'Errico
上次活动时间: 2024-12-19，16:48

Answers not displaying symbolic results? FIXED

syms u v
atan2alt(v,u)
ans = 
function Z = atan2alt(V,U)
% extension of atan2(V,U) into the complex plane
Z = -1i*log((U+1i*V)./sqrt(U.^2+V.^2));
% check for purely real input. if so, zero out the imaginary part.
realInputs = (imag(U) == 0) & (imag(V) == 0);
Z(realInputs) = real(Z(realInputs));
end
As I am editing this post, I see the expected symbolic display in the nice form as have grown to love. However, when I save the post, it does not display. (In fact, it shows up here in the discussions post.) This seems to be a new problem, as I have not seen that failure mode in the past.
You can see the problem in this Answer forum response of mine, where it did fail.
https://www.mathworks.com/matlabcentral/answers/2152250-atan2-does-not-accept-complex-numbers-as-input?s_tid=srchtitle
David
David
上次活动时间: 2024-9-12

Jokes in MATLAB

In case you haven't come across it yet, @Gareth created a Jokes toolbox to get MATLAB to tell you a joke.
https://www.mathworks.com/matlabcentral/fileexchange/172039-jokes-in-matlab/
As far as I know, starting from MATLAB R2024b, the documentation is defaulted to be accessed online. However, the problem is that every time I open the official online documentation through my browser, it defaults or forcibly redirects to the documentation hosted site for my current geographic location, often with multiple pop-up reminders, which is very annoying!
Suggestion: Could there be an option to set preferences linked to my personal account so that the documentation defaults to my chosen language preference without having to deal with “forced reminders” or “forced redirection” based on my geographic location? I prefer reading the English documentation, but the website automatically redirects me to the Chinese documentation due to my geolocation, which is quite frustrating!
----------------2024.12.13 update-----------------
Although the above issue was resolved by technical support, subsequent redirects are still causing severe delays...
MATLAB online documentation redirection is very time-consuming - MATLAB Answers - MATLAB Central
In the past two years, MATHWORKS has updated the image viewer and audio viewer, giving them a more modern interface with features like play, pause, fast forward, and some interactive tools that are more commonly found in typical third-party players. However, the video player has not seen any updates. For instance, the Video Viewer or vision.VideoPlayer could benefit from a more modern player interface. Perhaps I haven't found a suitable built-in player yet. It would be great if there were support for custom image processing and audio processing algorithms that could be played in a more modern interface in real time.
Additionally, I found it quite challenging to develop a modern video player from scratch in App Designer.（If there's a video component for that that would be great）
-----------------------------------------------------------------------------------------------------------------
BTW，the following picture shows the built-in function uihtml function showing a more modern playback interface with controls for play, pause and so on. But can not add real-time image processing algorithms within it.
goc3
goc3
上次活动时间: 2024-12-3

Congratulations to William!

I was browsing the MathWorks website and decided to check the Cody leaderboard. To my surprise, William has now solved 5,000 problems. At the moment, there are 5,227 problems on Cody, so William has solved over 95%. The next competitor is over 500 problems behind. His score is also clearly the highest, approaching 60,000.
Please take a moment to congratulate @William.
Steve Lenk
Steve Lenk
上次活动时间: 2024-9-7

Personal Best Downloads Level 2 Badge

Has this been eliminated? I've been at 31 or 32 for 30 days for awhile, but no badge. 10 badge was automatic.

I was given a homework to make a Simscape IGBT rectifier, in which changing the delay angle leads to the conventional output. The input is 220 V 50 Hz supply, there are 2 gate pulses which I am providing using pulse generators (period 1/50 and pulse width 50%). The output, however is not correct. I am attaching the circuit diagram

and the incorrect output for a delay angle (α) 60 degrees. Can somebody point out the mistake? Thank you.