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結果:

Source image https://www.linkedin.com/posts/tien-nguyen-a0795a99_this-is-one-of-the-most-breathtaking-photographs-activity-7398052712694722560-Xzxy/
% Recreation of Saturn photo
figure('Color', 'k', 'Position', [100, 100, 800, 800]);
ax = axes('Color', 'k', 'XColor', 'none', 'YColor', 'none', 'ZColor', 'none');
hold on;
% Create the planet sphere
[x, y, z] = sphere(150);
% Saturn colors - pale yellow/cream gradient
saturn_radius = 1;
% Create color data based on latitude for gradient effect
lat = asin(z);
color_data = rescale(lat, 0.3, 0.9);
% Plot Saturn with smooth shading
planet = surf(x*saturn_radius, y*saturn_radius, z*saturn_radius, ...
color_data, ...
'EdgeColor', 'none', ...
'FaceColor', 'interp', ...
'FaceLighting', 'gouraud', ...
'AmbientStrength', 0.3, ...
'DiffuseStrength', 0.6, ...
'SpecularStrength', 0.1);
% Use a cream/pale yellow colormap for Saturn
cream_map = [linspace(0.4, 0.95, 256)', ...
linspace(0.35, 0.9, 256)', ...
linspace(0.2, 0.7, 256)'];
colormap(cream_map);
% Create the ring system
n_points = 300;
theta = linspace(0, 2*pi, n_points);
% Define ring structure (inner radius, outer radius, brightness)
rings = [
1.2, 1.4, 0.7; % Inner ring
1.45, 1.65, 0.8; % A ring
1.7, 1.85, 0.5; % Cassini division (darker)
1.9, 2.3, 0.9; % B ring (brightest)
2.35, 2.5, 0.6; % C ring
2.55, 2.8, 0.4; % Outer rings (fainter)
];
% Create rings as patches
for i = 1:size(rings, 1)
r_inner = rings(i, 1);
r_outer = rings(i, 2);
brightness = rings(i, 3);
% Create ring coordinates
x_inner = r_inner * cos(theta);
y_inner = r_inner * sin(theta);
x_outer = r_outer * cos(theta);
y_outer = r_outer * sin(theta);
% Front side of rings
ring_x = [x_inner, fliplr(x_outer)];
ring_y = [y_inner, fliplr(y_outer)];
ring_z = zeros(size(ring_x));
% Color based on brightness
ring_color = brightness * [0.9, 0.85, 0.7];
fill3(ring_x, ring_y, ring_z, ring_color, ...
'EdgeColor', 'none', ...
'FaceAlpha', 0.7, ...
'FaceLighting', 'gouraud', ...
'AmbientStrength', 0.5);
end
% Add some texture/gaps in the rings using scatter
n_particles = 3000;
r_particles = 1.2 + rand(1, n_particles) * 1.6;
theta_particles = rand(1, n_particles) * 2 * pi;
x_particles = r_particles .* cos(theta_particles);
y_particles = r_particles .* sin(theta_particles);
z_particles = (rand(1, n_particles) - 0.5) * 0.02;
% Vary particle brightness
particle_colors = repmat([0.8, 0.75, 0.6], n_particles, 1) .* ...
(0.5 + 0.5*rand(n_particles, 1));
scatter3(x_particles, y_particles, z_particles, 1, particle_colors, ...
'filled', 'MarkerFaceAlpha', 0.3);
% Add dramatic outer halo effect - multiple layers extending far out
n_glow = 20;
for i = 1:n_glow
glow_radius = 1 + i*0.35; % Extend much farther
alpha_val = 0.08 / sqrt(i); % More visible, slower falloff
% Color gradient from cream to blue/purple at outer edges
if i <= 8
glow_color = [0.9, 0.85, 0.7]; % Warm cream/yellow
else
% Gradually shift to cooler colors
mix = (i - 8) / (n_glow - 8);
glow_color = (1-mix)*[0.9, 0.85, 0.7] + mix*[0.6, 0.65, 0.85];
end
surf(x*glow_radius, y*glow_radius, z*glow_radius, ...
ones(size(x)), ...
'EdgeColor', 'none', ...
'FaceColor', glow_color, ...
'FaceAlpha', alpha_val, ...
'FaceLighting', 'none');
end
% Add extensive glow to rings - make it much more dramatic
n_ring_glow = 12;
for i = 1:n_ring_glow
glow_scale = 1 + i*0.15; % Extend farther
alpha_ring = 0.12 / sqrt(i); % More visible
for j = 1:size(rings, 1)
r_inner = rings(j, 1) * glow_scale;
r_outer = rings(j, 2) * glow_scale;
brightness = rings(j, 3) * 0.5 / sqrt(i);
x_inner = r_inner * cos(theta);
y_inner = r_inner * sin(theta);
x_outer = r_outer * cos(theta);
y_outer = r_outer * sin(theta);
ring_x = [x_inner, fliplr(x_outer)];
ring_y = [y_inner, fliplr(y_outer)];
ring_z = zeros(size(ring_x));
% Color gradient for ring glow
if i <= 6
ring_color = brightness * [0.9, 0.85, 0.7];
else
mix = (i - 6) / (n_ring_glow - 6);
ring_color = brightness * ((1-mix)*[0.9, 0.85, 0.7] + mix*[0.65, 0.7, 0.9]);
end
fill3(ring_x, ring_y, ring_z, ring_color, ...
'EdgeColor', 'none', ...
'FaceAlpha', alpha_ring, ...
'FaceLighting', 'none');
end
end
% Add diffuse glow particles for atmospheric effect
n_glow_particles = 8000;
glow_radius_particles = 1.5 + rand(1, n_glow_particles) * 5;
theta_glow = rand(1, n_glow_particles) * 2 * pi;
phi_glow = acos(2*rand(1, n_glow_particles) - 1);
x_glow = glow_radius_particles .* sin(phi_glow) .* cos(theta_glow);
y_glow = glow_radius_particles .* sin(phi_glow) .* sin(theta_glow);
z_glow = glow_radius_particles .* cos(phi_glow);
% Color particles based on distance - cooler colors farther out
particle_glow_colors = zeros(n_glow_particles, 3);
for i = 1:n_glow_particles
dist = glow_radius_particles(i);
if dist < 3
particle_glow_colors(i,:) = [0.9, 0.85, 0.7];
else
mix = (dist - 3) / 4;
particle_glow_colors(i,:) = (1-mix)*[0.9, 0.85, 0.7] + mix*[0.5, 0.6, 0.9];
end
end
scatter3(x_glow, y_glow, z_glow, rand(1, n_glow_particles)*2+0.5, ...
particle_glow_colors, 'filled', 'MarkerFaceAlpha', 0.05);
% Lighting setup
light('Position', [-3, -2, 4], 'Style', 'infinite', ...
'Color', [1, 1, 0.95]);
light('Position', [2, 3, 2], 'Style', 'infinite', ...
'Color', [0.3, 0.3, 0.4]);
% Camera and view settings
axis equal off;
view([-35, 25]); % Angle to match saturn_photo.jpg - more dramatic tilt
camva(10); % Field of view - slightly wider to show full halo
xlim([-8, 8]); % Expanded to show outer halo
ylim([-8, 8]);
zlim([-8, 8]);
% Material properties
material dull;
title('Saturn - Left click: Rotate | Right click: Pan | Scroll: Zoom', 'Color', 'w', 'FontSize', 12);
% Enable interactive camera controls
cameratoolbar('Show');
cameratoolbar('SetMode', 'orbit'); % Start in rotation mode
% Custom mouse controls
set(gcf, 'WindowButtonDownFcn', @mouseDown);
function mouseDown(src, ~)
selType = get(src, 'SelectionType');
switch selType
case 'normal' % Left click - rotate
cameratoolbar('SetMode', 'orbit');
rotate3d on;
case 'alt' % Right click - pan
cameratoolbar('SetMode', 'pan');
pan on;
end
end
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Reinaldo
Reinaldo
最後のアクティビティ: 2025 年 11 月 19 日 16:04

Is MATLAB Worth It If You Can’t Compile with sym, zeta, or lambertw?

Developing an application in MATLAB often feels like a natural choice: it offers a unified environment, powerful visualization tools, accessible syntax, and a robust technical ecosystem. But when the goal is to build a compilable, distributable app, the path becomes unexpectedly difficult if your workflow depends on symbolic functions like sym, zeta, or lambertw.
This isn’t a minor technical inconvenience—it’s a structural contradiction. MATLAB encourages the creation of graphical interfaces, input validation, and dynamic visualization. It even provides an Application Compiler to package your code. But the moment you invoke sym, the compiler fails. No clear warning. No workaround. Just: you cannot compile. The same applies to zeta and lambertw, which rely on the symbolic toolbox.
So we’re left asking: how can a platform designed for scientific and technical applications block compilation of functions that are central to those very disciplines?
What Are the Alternatives?
  • Rewrite everything numerically, avoiding symbolic logic—often impractical for advanced mathematical workflows.
  • Use partial workarounds like matlabFunction, which may work but rarely preserve the original logic or flexibility.
  • Switch platforms (e.g., Python with SymPy, Julia), which means rebuilding the architecture and leaving behind MATLAB’s ecosystem.
So, Is MATLAB Still Worth It?
That’s the real question. MATLAB remains a powerful tool for prototyping, teaching, analysis, and visualization. But when it comes to building compilable apps that rely on symbolic computation, the platform imposes limits that contradict its promise.
Is it worth investing time in a MATLAB app if you can’t compile it due to essential mathematical functions? Should MathWorks address this contradiction? Or is it time to rethink our tools?
I’d love to hear your thoughts. Is MATLAB still worth it for serious application development?
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Toshiaki Takeuchi
Toshiaki Takeuchi
最後のアクティビティ: 2025 年 11 月 13 日 3:35

Where do you fall in terms of the AI adoption curve for coding?

Experimenting with Agentic AI
44%
I am an AI skeptic
0%
AI is banned at work
11%
I am happy with Conversational AI
44%
9 票
Adam Danz
Adam Danz
最後のアクティビティ: 2025 年 11 月 12 日 13:42

Sparklines and interactive data exploration

It’s exciting to dive into a new dataset full of unfamiliar variables but it can also be overwhelming if you’re not sure where to start. Recently, I discovered some new interactive features in MATLAB live scripts that make it much easier to get an overview of your data. With just a few clicks, you can display sparklines and summary statistics using table variables, sort and filter variables, and even have MATLAB generate the corresponding code for reproducibility.
The Graphics and App Building blog published an article that walks through these features showing how to explore, clean, and analyze data—all without writing any code.
If you’re interested in streamlining your exploratory data analysis or want to see what’s new in live scripts, you might find it helpful:
Exploratory Data Analysis using Sparklines and Summary Statistics in Live Scripts
If you’ve tried these features or have your own tips for quick data exploration in MATLAB, I’d love to hear your thoughts!
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Ludvig Nordin
Ludvig Nordin
最後のアクティビティ: 2025 年 11 月 13 日 1:24

Which is your favorite?

Pure Matlab
82%
Simulink
18%
11 票
Saumya
Saumya
最後のアクティビティ: 2025 年 11 月 10 日 13:53

Looking for Internship Guidance as a Beginner MATLAB/Simulink Learner

Title: Looking for Internship Guidance as a Beginner MATLAB/Simulink Learner
Hello everyone,
I’m a Computer Science undergraduate currently building a strong foundation in MATLAB and Simulink. I’m still at a beginner level, but I’m actively learning every day and can work confidently once I understand the concepts. Right now I’m focusing on MATLAB modeling, physics simulation, and basic control systems so that I can contribute effectively to my current project.
I’m part of an Autonomous Underwater Vehicle (AUV) team preparing for the Singapore AUV Challenge (SAUVC). My role is in physics simulation, controls, and navigation, and MATLAB/Simulink plays a major role in that pipeline. I enjoy physics and mathematics deeply, which makes learning modeling and simulation very exciting for me.
On the coding side, I practice competitive programming regularly—
• Codeforces rating: ~1200
• LeetCode rating: ~1500
So I'm comfortable with logic-building and problem solving. What I’m looking for:
I want to know how a beginner like me can start applying for internships related to MATLAB, Simulink, modeling, simulation, or any engineering team where MATLAB is widely used (including companies outside MathWorks).
I would really appreciate advice from the community on:
  • What skills should I strengthen first?
  • Which MATLAB/Simulink toolboxes are most important for beginners aiming toward simulation/control roles?
  • What small projects or portfolio examples should I build to improve my profile?
  • What is the best roadmap to eventually become a good candidate for internships in this area?
Any guidance, resources, or suggestions would be extremely helpful for me.
Thank you in advance to everyone who shares their experience!
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Jorge Bernal-AlvizJorge Bernal-Alviz shared the following code that requires R2025a or later:
Test()
Warning: Hardware-accelerated graphics is unavailable. Displaying fewer markers to preserve interactivity.
function Test()
duration = 10;
numFrames = 800;
frameInterval = duration / numFrames;
w = 400;
t = 0;
i_vals = 1:10000;
x_vals = i_vals;
y_vals = i_vals / 235;
r = linspace(0, 1, 300)';
g = linspace(0, 0.1, 300)';
b = linspace(1, 0, 300)';
r = r * 0.8 + 0.1;
g = g * 0.6 + 0.1;
b = b * 0.9 + 0.1;
customColormap = [r, g, b];
figure('Position', [100, 100, w, w], 'Color', [0, 0, 0]);
axis equal;
axis off;
xlim([0, w]);
ylim([0, w]);
hold on;
colormap default;
colormap(customColormap);
plothandle = scatter([], [], 1, 'filled', 'MarkerFaceAlpha', 0.12);
for i = 1:numFrames
t = t + pi/240;
k = (4 + 3 * sin(y_vals * 2 - t)) .* cos(x_vals / 29);
e = y_vals / 8 - 13;
d = sqrt(k.^2 + e.^2);
c = d - t;
q = 3 * sin(2 * k) + 0.3 ./ (k + 1e-10) + ...
sin(y_vals / 25) .* k .* (9 + 4 * sin(9 * e - 3 * d + 2 * t));
points_x = q + 30 * cos(c) + 200;
points_y = q .* sin(c) + 39 * d - 220;
points_y = w - points_y;
CData = (1 + sin(0.1 * (d - t))) / 3;
CData = max(0, min(1, CData));
set(plothandle, 'XData', points_x, 'YData', points_y, 'CData', CData);
brightness = 0.5 + 0.3 * sin(t * 0.2);
set(plothandle, 'MarkerFaceAlpha', brightness);
drawnow;
pause(frameInterval);
end
end
https://www.linkedin.com/feed/update/urn:li:activity:7392574790642913280/
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David
David
最後のアクティビティ: 2025 年 11 月 6 日 20:47

Parallel Computing Onramp is here!

Parallel Computing Onramp is here! This free, one-hour self-paced course teaches the basics of running MATLAB code in parallel using multiple CPU cores, helping users speed up their code and write code that handles information efficiently.
Remember, Onramps are free for everyone - give the new course a try if you're curious. Let us know what you think of it by replying below.
https://matlabacademy.mathworks.com/details/parallel-computing-onramp/orpc

Parallel Computing Onramp | Self-Paced Online Courses - MATLAB & Simulink

Learn to speed up your MATLAB code by using multiple CPU cores to run for-loops in parallel and writing code that handles information efficiently.

matlabacademy.mathworks.com

From my experience, MATLAB's Deep Learning Toolbox is quite user-friendly, but it still falls short of libraries like PyTorch in many respects. Most users tend to choose PyTorch because of its flexibility, efficiency, and rich support for many mathematical operators. In recent years, the number of dlarray-compatible mathematical functions added to the toolbox has been very limited, which makes it difficult to experiment with many custom networks. For example, svd is currently not supported for dlarray inputs.
This link (List of Functions with dlarray Support - MATLAB & Simulink) lists all functions that support dlarray as of R2026a — only around 200 functions (including toolbox-specific ones). I would like to see support for many more fundamental mathematical functions so that users have greater freedom when building and researching custom models. For context, the core MATLAB mathematics module contains roughly 600 functions, and many application domains build on that foundation.
I hope MathWorks will prioritize and accelerate expanding dlarray support for basic math functions. Doing so would significantly increase the Deep Learning Toolbox's utility and appeal for researchers and practitioners.
Thank you.
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David
David
最後のアクティビティ: 2025 年 11 月 3 日 20:06

MATLAB MCP Core Server released on GitHub

Run MATLAB using AI applications by leveraging MCP. This MCP server for MATLAB supports a wide range of coding agents like Claude Code and Visual Studio Code.
Check it out and share your experiences below. Have fun!
GitHub repo: https://github.com/matlab/matlab-mcp-core-server
Yann Debray's blog post: https://blogs.mathworks.com/deep-learning/2025/11/03/releasing-the-matlab-mcp-core-server-on-github/

Releasing the MATLAB MCP Core Server on GitHub

This blog post is co-authored with Akshay Paul, the product manager for the new MATLAB MCP Core Server that released on Friday 31st of October on GitHub: github.com/matlab/matlab-mcp-core-server The AI Copy & Paste problem If you are like me, you are probably familiar with this situation. Going to your favorite chat app (ChatGPT® or Claude® for instance) and asking a question about MATLAB.

blogs.mathworks.com

I am excited to join this community to learn the more particularly the Matlab/Simulink
David
David
最後のアクティビティ: 2025 年 10 月 20 日

Shortcut to MATLAB Online - matlab.new

I just learned you can access MATLAB Online from the following shortcut in your web browser: https://matlab.new
Thanks @Yann Debray
From his recent blog post: pip & uv in MATLAB Online » Artificial Intelligence - MATLAB & Simulink
Muhammad Saim
Muhammad Saim
最後のアクティビティ: 2025 年 10 月 19 日

Looking for Co-Trainers: Comprehensive MATLAB Programming Course

I'm developing a comprehensive MATLAB programming course and seeking passionate co-trainers to collaborate!
Why MATLAB Matters:Many people underestimate MATLAB's significance in:
  • Communication systems
  • Signal processing
  • Mathematical modeling
  • Engineering applications
  • Scientific computing
Course Structure:
  1. Foundation Module: MATLAB basics and fundamentals
  2. Image Processing: Practical applications and techniques
  3. Signal Processing: Analysis and implementation
  4. Machine Learning: ML algorithms using MATLAB
  5. Hands-on Learning: Projects, assignments.
What I'm Looking For:
  • Enthusiastic educators willing to share knowledge
  • Experience in any MATLAB application area
  • Commitment to collaborative teaching
Interested in joining as a co-trainer? Please comment below or reach out directly!
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xingxingcui
xingxingcui
最後のアクティビティ: 2025 年 11 月 10 日 9:34

How Should MATLAB's Help Documentation Be Presented?

Online Doc + System Browser
11%
Online Doc + Dedicated Browser
11%
Offline Doc +System Browser
11%
Offline Doc + Dedicated Browser
23%
Hybrid Approach (Support All Modes)
23%
User-Definable / Fully Configurable
20%
35 票
Toshiaki Takeuchi
Toshiaki Takeuchi
最後のアクティビティ: 2025 年 10 月 22 日

R2026a prerelease is available for download for eligible users

You can find it here https://www.mathworks.com/products/new_products/release-highlights.html

Prerelease Release Highlights

R2025a prerelease: Updates to MATLAB, Simulink, and more than 100 other products.

www.mathworks.com

I'm working on training neural networks without backpropagation / automatic differentiation, using locally derived analytic forms of update rules. Given that this allows a direct formula to be derived for the update rule, it removes alot of the overhead that is otherwise required from automatic differentiation.
However, matlab's functionalities for neural networks are currently solely based around backpropagation and automatic differentiation, such as the dlgradient function and requiring everything to be dlarrays during training.
I have two main requests, specifically for functions that perform a single operation within a single layer of a neural network, such as "dlconv", "fullyconnect", "maxpool", "avgpool", "relu", etc:
  • these functions should also allow normal gpuArray data instead of requiring everything to be dlarrays.
  • these functions are currently designed to only perform the forward pass. I request that these also be designed to perform the backward pass if user requests. There can be another input user flag that can be "forward" (default) or "backward", and then the function should have all the necessary inputs to perform that operation (e.g. for "avgpool" forward pass it only needs the avgpool input data and the avgpool parameters, but for the "avgpool" backward pass it needs the deriviative w.r.t. the avgpool output data, the avgpool parameters, and the original data dimensions). I know that there is a maxunpool function that achieves this for maxpool, but it has significant issues when trying to use it this way instead of by backpropagation in a dlgradient type layer, see (https://www.mathworks.com/matlabcentral/answers/2179587-making-a-custom-way-to-train-cnns-and-i-am-noticing-that-avgpool-is-significantly-faster-than-maxpo?s_tid=srchtitle).
I don't know how many people would benefit from this feature, and someone could always spend their time creating these functionalities themselves by matlab scripts, cuDNN mex, etc., but regardless it would be nice for matlab to have this allowable for more customizable neural net training.
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Inspired by @xingxingcui's post about old MATLAB versions and @유장's post about an old Easter egg, I thought it might be fun to share some MATLAB-Old-Timer Stories™.
Back in the early 90s, MATLAB had been ported to MacOS, but there were some interesting wrinkles. One that kept me earning my money as a computer lab tutor was that MATLAB required file names to follow Windows standards - no spaces or other special characters. But on a Mac, nothing stopped you from naming your script "hello world - 123.m". The problem came when you tried to run it. MATLAB was essentially doing an eval on the script name, assuming the file name would follow Windows (and MATLAB) naming rules.
So now imagine a lab full of students taking a university course. As is common in many universities, the course was given a numeric code. For whatever historical reason, my school at that time was also using numeric codes for the departments. Despite being told the rules for naming scripts, many students would default to something like "26.165 - 1.1" for problem one on HW1 for the intro applied math course 26.165.
No matter what they did in their script, when they ran it, MATLAB would just say "ans = 25.0650".
Nothing brings you more MATLAB-god credibility as a student tutor than walking over to someone's computer, taking one look at their output, saying "rename your file", and walking away like a boss.
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Mike Croucher
Mike Croucher
最後のアクティビティ: 2025 年 10 月 13 日

What resources do you use to learn more about MATLAB and Simulink?

I recently published this blog post about resources to help people learn MATLAB https://blogs.mathworks.com/matlab/2025/09/11/learning-matlab-in-2025/
What are your favourite MATLAB learning resources?

Learning MATLAB in 2025

I've been using MATLAB for almost 30 years, man and boy. In those 30 years, not only has MATLAB itself changed a lot but how you learn it has also changed dramatically. Back in my day, we had a few lectures backed by a textbook and we were grateful. Anything deeper than that required diving into the documentation, all of

blogs.mathworks.com

xingxingcui
xingxingcui
最後のアクティビティ: 2025 年 10 月 13 日

Looking back at the first MATLAB version I use

It was 2010 when I was a sophomore in university. I chose to learn MATLAB because of a mathematical modeling competition, and the university provided MATLAB 7.0, a very classic release. To get started, I borrowed many MATLAB books from the library and began by learning simple numerical calculations, plotting, and solving equations. Gradually I was drawn in by MATLAB’s powerful capabilities and became interested; I often used it as a big calculator for fun. That version didn’t have MATLAB Live Script; instead it used MATLAB Notebook (M-Book), which allowed MATLAB functions to be used directly within Microsoft Word, and it also had the Symbolic Math Toolbox’s MuPAD interactive environment. These were later gradually replaced by Live Scripts introduced in R2016a. There are many similar examples...
Out of curiosity, I still have screenshots on my computer showing MATLAB 7.0 running compatibly. I’d love to hear your thoughts?
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Paul
Paul
最後のアクティビティ: 2025 年 10 月 15 日

It is Time for the Symbolic Math Toolbox to Include dot and cross Functions

Edit 15 Oct 2025: Removed incorrect code. Replaced symmatrix2sym and symfunmatrix2symfun with sym and symfun respectively (latter supported as of 2024b).
The Symbolic Math Toolbox does not have its own dot and and cross functions. That's o.k. (maybe) for garden variety vectors of sym objects where those operations get shipped off to the base Matlab functions
x = sym('x',[3,1]); y = sym('y',[3,1]);
which dot(x,y)
/MATLAB/toolbox/matlab/specfun/dot.m
dot(x,y)
ans = 
which cross(x,y)
/MATLAB/toolbox/matlab/specfun/cross.m
cross(x,y)
ans = 
But now we have symmatrix et. al., and things don't work as nicely
clearvars
x = symmatrix('x',[3,1]); y = symmatrix('y',[3,1]);
z = symmatrix('z',[1,1]);
sympref('AbbreviateOutput',false);
dot() expands the result, which isn't really desirable for exposition.
eqn = z == dot(x,y)
eqn = 
Also, dot() returns the the result in terms of the conjugate of x, which can't be simplifed away at the symmatrix level
assumeAlso(sym(x),'real')
class(eqn)
ans = 'symmatrix'
try
eqn = z == simplify(dot(x,y))
catch ME
ME.message
end
ans = 'Undefined function 'simplify' for input arguments of type 'symmatrix'.'
To get rid of the conjugate, we have to resort to sym
eqn = simplify(sym(eqn))
eqn = 
but again we are in expanded form, which defeats the purpose of symmatrix (et. al.)
But at least we can do this to get a nice equation
eqn = z == x.'*y
eqn = 
dot errors with symfunmatrix inputs
clearvars
syms t real
x = symfunmatrix('x(t)',t,[3,1]); y = symfunmatrix('y(t)',t,[3,1]);
try
dot(x,y)
catch ME
ME.message
end
ans = 'Invalid argument at position 2. Symbolic function is evaluated at the input arguments and does not accept colon indexing. Instead, use FORMULA on the function and perform colon indexing on the returned output.'
Cross works (accidentally IMO) with symmatrix, but expands the result, which isn't really desirable for exposition
clearvars
x = symmatrix('x',[3,1]); y = symmatrix('y',[3,1]);
z = symmatrix('z',[3,1]);
eqn = z == cross(x,y)
eqn = 
And it doesn't work at all if an input is a symfunmatrix
syms t
w = symfunmatrix('w(t)',t,[3,1]);
try
eqn = z == cross(x,w);
catch ME
ME.message
end
ans = 'A and B must be of length 3 in the dimension in which the cross product is taken.'
In the latter case we can expand with
eqn = z == cross(sym(x),symfun(w)) % x has to be converted
eqn(t) = 
But we can't do the same with dot (as shown above, dot doesn't like symfun inputs)
try
eqn = z == dot(sym(x),symfun(w))
catch ME
ME.message
end
ans = 'Invalid argument at position 2. Symbolic function is evaluated at the input arguments and does not accept colon indexing. Instead, use FORMULA on the function and perform colon indexing on the returned output.'
Looks like the only choice for dot with symfunmatrix is to write it by hand at the matrix level
x.'*w
ans(t) = 
or at the sym/symfun level
sym(x).'*symfun(w) % assuming x is real
ans(t) = 
Ideally, I'd like to see dot and cross implemented for symmatrix and symfunmatrix types where neither function would evaluate, i.e., expand, until both arguments are subs-ed with sym or symfun objects of appropriate dimension.
Also, it would be nice if symmatrix could be assumed to be real. Is there a reason why being able to do so wouldn't make sense?
try
assume(x,'real')
catch ME
ME.message
end
ans = 'Undefined function 'assume' for input arguments of type 'symmatrix'.'
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