結果:
在分类学习器中，点击特征选择，页面就会一直停留在正在打开特征选择选项。然后命令行窗口会出现警告。警告的内容为警告: 执行为类 mlearnapp.internal.ui.toolstrip.GenericButtonView 定义的事件 Clicked 的侦听程序回调时出现错误:
错误使用 normalize
输入参数太多。
In the classification learner, click Feature Selection and the page will stay with the feature selection option open. A warning will then appear in the command line window. Warning for warning: the contents of execution for the class mlearnapp. Internal. UI. Toolstrip. GenericButtonView defined event Clicked listener error correction:
Use normalize incorrectly
Too many input parameters.
I am looking for a Simulink tutor to help me with Reinforcement Learning Agent integration. If you work for MathWorks, I am willing to pay $30/hr. I am working on a passion project, ready to start ASAP. DM me if you're interested.
Bitte um Hilfe beim Kauf
I love it all
45%
Love the first snowfall only
15%
Hate it
17.5%
It doesn't snow where I live
22.5%
40 票
Since May 2023, MathWorks officially introduced the new Community API(MATLAB Central Interface for MATLAB), which supports both MATLAB and Node.js languages, allowing users to programmatically access data from MATLAB Answers, File Exchange, Blogs, Cody, Highlights, and Contests.
I’m curious about what interesting things people generally do with this API. Could you share some of your successful or interesting experiences? For example, retrieving popular Q&A topics within a certain time frame through the API and displaying them in a chart.
If you have any specific examples or ideas in mind, feel free to share!
function Shrinking_bvp4c
clc
clear all
clear all
% defining parameters
k=0.5,K=0.8,M=0.3,S=2.0;
sol1 = bvpinit(linspace(0,20,25),[1 1 1 0]);
sol = bvp4c(@bvp2D,@bc2D,sol1);
x = sol.x;
y = sol.y;
%%% Plotting of the velocity
figure (1)
plot(x, y(2, :) ,'linewidth', 1)
hold on
xlabel('\eta', 'fontweight', 'bold', 'fontsize', 16)
ylabel('f^{\prime}(\eta)', 'fontweight', 'bold', 'fontsize', 16)
%% Residual of the boundary conditions
function residual = bc2D(y0, yinf)
residual=[y0(1)-S; y0(2) - 1; yinf(2)];
end
%% System of First Order ODEs
function yvector = bvp2D(t,y)
yy1 = 1/y(1)*(y(2)*y(2)-y(1)*y(3)-y(4)+k*(2*y(2)*y(4)-y(3)*y(3))+M*y(2)+K*y(2));
yvector = [y(2);y(3);yy1];
end
end
On my computers, this bit of code produces an error whose cause I have pinpointed,
load tstcase
ycp=lsqlin(I, y, Aineq, bineq);
Error using parseOptions
Too many output arguments.
Error in lsqlin (line 170)
[options, optimgetFlag] = parseOptions(options, 'lsqlin', defaultopt);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The reason for the error is seemingly because, in recent Matlab, lsqlin now depends on a utility function parseOptions, which is shadowed by one of my personal functions sharing the same name:
C:\Users\MWJ12\Documents\mwjtree\misc\parseOptions.m
C:\Program Files\MATLAB\R2024b\toolbox\shared\optimlib\parseOptions.m % Shadowed
The MathWorks-supplied version of parseOptions is undocumented, and so is seemingly not meant for use outside of MathWorks. Shouldn't it be standard MathWorks practice to put these utilities in a private\ folder where they cannot conflict with user-supplied functions of the same name?
It is going to be an enormous headache for me to now go and rename all calls to my version of parseOptions. It is a function I have been using for a long time and permeates my code.
General observations on practical implementation issues regarding add-on versioning
I am making updates to one of my File Exchange add-ons, and the updates will require an updated version of another add-on. The state of versioning for add-ons seems to be a bit of a mess.
First, there are several sources of truth for an add-on’s version:
- The GitHub release version, which gets mirrored to the File Exchange version
- The ToolboxVersion property of toolboxOptions (for an add-on packaged as a toolbox)
- The version in the Contents.m file (if there is one)
Then, there is the question of how to check the version of an installed add-on. You can call matlab.addon.installedAddons, which returns a table. Then you need to inspect the table to see if a particular add-on is present, if it is enabled, and get the version number.
If you can get the version number this way, then you need some code to compare two semantic version numbers (of the form “3.1.4”). I’m not aware of a documented MATLAB function for this. The verLessThan function takes a toolbox name and a version; it doesn’t help you with comparing two versions.
If add-on files were downloaded directly and added to the MATLAB search path manually, instead of using the .mtlbx installer file, the add-on won’t be listed in the table returned by matlab.addon.installedAddon. You’d have to call ver to get the version number from the Contents.m file (if there is one).
Frankly, I don’t want to write any of this code. It would take too long, be challenging to test, and likely be fragile.
Instead, I think I will write some sort of “capabilities” utility function for the add-on. This function will be used to query the presence of needed capabilities. There will still be a slight coding hassle—the client add-on will need to call the capabilities utility function in a try-catch, because earlier versions of the add-on will not have that utility function.
I also posted this over at Harmonic Notes
Have you ever wanted to search for a community member but didn't know where to start? Or perhaps you knew where to search but couldn't find enough information from the results? You're not alone. Many community users have shared this frustration with us. That's why the community team is excited to introduce the new ‘People’ page to address this need.
What Does the ‘People’ Page Offer?
- Comprehensive User Search: Search for users across different applications seamlessly.
- Detailed User Information: View a list of community members along with additional details such as their join date, rankings, and total contributions.
- Sorting Options: Use the ‘sort by’ filter located below the search bar to organize the list according to your preferences.
- Easy Navigation: Access the Answers, File Exchange, and Cody Leaderboard by clicking the ‘Leaderboards’ button in the upper right corner.
In summary, the ‘People’ page provides a gateway to search for individuals and gain deeper insights into the community.
How Can You Access It?
Navigate to the global menu, click on the ‘More’ link, and you’ll find the ‘People’ option.
Now you know where to go if you want to search for a user. We encourage you to give it a try and share your feedback with us.
Los invito a conocer el libro "Sistemas dinámicos en contexto: Modelación matemática, simulación, estimación y control con MATLAB", el cual ya está disponible en formato digital.
El libro integra diversos temas de los sistemas dinámicos desde un punto de vista práctico utilizando programas de MATLAB y simulaciones en Simulink y utilizando métodos numéricos (ver enlace). Existe mucho material en el blog del libro con posibilidades para comentarios, propuestas y correcciones. Resalto los casos de estudio
Creo que el libro les puede dar un buen panorama del área con la posibilidad de experimentar de manera interactiva con todo el material de MATLAB disponible en formato Live Script. Lo mejor es que se pueden formular preguntas en el blog y hacer propuestas al autor de ejercicios resueltos.
Son bienvenidos los comentarios, sugerencias y correcciones al texto.
Simulink has been an essential tool for modeling and simulating dynamic systems in MATLAB. With the continuous advancements in AI, automation, and real-time simulation, I’m curious about what the future holds for Simulink.
What improvements or new features do you think Simulink will have in the coming years? Will AI-driven modeling, cloud-based simulation, or improved hardware integration shape the next generation of Simulink?
I have already created a 8-DOF electric vehicle model in MATLAB and during the verification method, I noticed that the roll angle does not really align with the data from CarMaker. I would like to seek for the oppinion from this community on how to improve the graph that I have obtained. I have also attatched the parameters of this vehicle as well as the graph that I have obtained. The blue plots indicates the data from a real world based electric model from CarMaker and yellow is from the 8-DOF model in matlab.
these are the vehicle parameters
data.g = 9.81; % [m/s^2] acceleration of gravity
data.f_res = 1.1e-2; % [-] rolling friction parameter
data.k_res = 6.5e-7; % [s^2/m^2] rolling friction coefficient
data.rho = 1.205; % [kg/m^3] air density
data.area = 2.156; % [m^2] cross section
data.cx = 0.30; % [-] drag coefficient
data.mass = 2200.10; % [kg] total vehicle mass
data.Jx = 552.75; % [kg*m^2] roll-axis inertia
data.Jz = 3002.5; % [kg*m^2] yaw-axis inertia
data.Jw = 2; % [kg*m^2] spin-axis inertia of wheel
data.radius = 0.3401; % [m] wheel radius
% Reduced Pacejka tyre model data
data.tyre_par(1) = 82.8868; % Pacejka coeff.
data.tyre_par(2) = 1.2070; % Pacejka coeff.
data.tyre_par(3) = 1.1351; % Pacejka coeff.
data.tyre_par(4) = 14.4035; % Pacejka coeff.
data.tyre_par(5) = 1.1932; % Pacejka coeff.
data.tyre_par(6) = -0.0001; % Pacejka coeff.
data.tyre_par(7) = 2.1219; % Pacejka coeff.
% Pacejka 5.2 tyre model data
tyre = ImportTyreData('.', 'Tyre_VSM.tir');
tyre = rmfield(tyre, 'file');
data.tyre_par_full = tyre;
data.wbase_f = 1.4727; % [m] front wheelbase
data.wbase_r = 1.4553; % [m] rear wheelbase
data.wbase = data.wbase_f + data.wbase_r; % [m] wheelbase
data.track = 1.655; % [m] track
data.h_cg = 0.631; % [m] centre of gravity height from ground
data.h_roll = 0.091; % [m] roll centre height from ground
data.k_roll_f = 8.67e4; % [Nm] roll stiffness at front
data.k_roll_r = 7.80e4; % [Nm] roll stiffness at rear
data.c_roll_f = 1.2e6; % [Nm/s] roll damping at front
data.c_roll_r = 6e5; % [Nm/s] roll damping at rear
data.k_act_roll = 0.9; % [-] active anti-roll coefficient
data.em_curve = [ % electric motor torque-speed curve
0, 900, 1000, 1100, 1200, 1300 % [RPM]
1500, 1500, 1400, 1000, 500, 0 % [Nm]
];
data.torque_bk_lb = -5e3; % [Nm] minimum brake torque
I am very pleased to share my book, with coauthors Professor Richard Davis and Associate Professor Sam Toan, titled "Chemical Engineering Analysis and Optimization Using MATLAB" published by Wiley: https://www.wiley.com/en-us/Chemical+Engineering+Analysis+and+Optimization+Using+MATLAB-p-9781394205363
Also in The MathWorks Book Program:
Chemical Engineering Analysis and Optimization Using MATLAB® introduces cutting-edge, highly in-demand skills in computer-aided design and optimization. With a focus on chemical engineering analysis, the book uses the MATLAB platform to develop reader skills in programming, modeling, and more. It provides an overview of some of the most essential tools in modern engineering design.
Chemical Engineering Analysis and Optimization Using MATLAB® readers will also find:
- Case studies for developing specific skills in MATLAB and beyond
- Examples of code both within the text and on a companion website
- End-of-chapter problems with an accompanying solutions manual for instructors
This textbook is ideal for advanced undergraduate and graduate students in chemical engineering and related disciplines, as well as professionals with backgrounds in engineering design.
You've probably heard about the DeepSeek AI models by now. Did you know you can run them on your own machine (assuming its powerful enough) and interact with them on MATLAB?
In my latest blog post, I install and run one of the smaller models and start playing with it using MATLAB.
Larger models wouldn't be any different to use assuming you have a big enough machine...and for the largest models you'll need a HUGE machine!
Even tiny models, like the 1.5 billion parameter one I demonstrate in the blog post, can be used to demonstrate and teach things about LLM-based technologies.
Have a play. Let me know what you think.
My intention is to generate th code as mentioned below
void computeArea() {
rectangle.area = rectangle.length * rectangle.width;
}
This is the question I am trying to solve and I also uploading the code i have written and error I am getting, Please help me the error please.
Currently, according to the official documentation, "DisplayName" only supports character vectors or single scalar string as input. For example, when plotting three variables simultaneously, if I use a single scalar string as input, the legend labels will all be the same. To have different labels, I need to specify them separately using the legend function with label1, label2, label3.
Here's an example illustrating the issue:
x = (1:10)';
y1 = x;
y2 = x.^2;
y3 = x.^3;
% Plotting with a string scalar for DisplayName
figure;
plot(x, [y1,y2,y3], DisplayName="y = x");
legend;
% To have different labels, I need to use the legend function separately
figure;
plot(x, [y1,y2,y3], DisplayName=["y = x","y = x^2","y=x^3"]);
% legend("y = x","y = x^2","y=x^3");
Hi!
I’m facing a problem in which I need an “intermediate” level of detail for my simulation.
In my case, I’d like to simulate a radar altimeter flying at low altitude over some terrain or sea. Over this surface, suppose to have an obstacle (tree/house/ship/…). I know everything about my altimeter (pulsed radar, frenquency, pulse duration, beam width, …). A possible outcome of such a simulation could be the assessment of the impact of different gain patterns on the received pulse.
What I have always found on the internet are either too simple solution (like solving the radar equations) or too complex (Method of Moments, or similar approaches).
Regarding the radar equation, I have always wandered how it can deal with the echoes coming from the outer regions of the beamwidth of the altimeter antenna (the equation only has the boresight gain as input parameter).
On the other hand, in my opinion, approaches like MoM are really too complicated and beyond my scope.
I had a look and tried to implement some of the Matlab functions that already exist (e.g., the ones on the FMCW Radar Altimeter Simulation example), but I don’t think they meet my needs.
So I decided to try to write my own code, providing the shape of the terrain/sea surface, the shape for the obstacles (for now, just simple shapes)… I guess I’d have to sample the domain, evaluating the echoes for all these elements… however, even in this case there are a lot of parameters that I don’t know how to handle properly, for example: - is it reasonable to discretize terrain or sea instead of assuming some model for the backscatter? - how should the domain be discretized? - how can I guarantee the conservation of power, considering the effects of the radiation pattern of the antenna and the aforementioned discretization of the domain?
Thanks in advance for your support.
Best regards, Alessandro
私の場合、前の会社が音楽認識アプリの会社で、アルゴリズム開発でFFTが使われていたことがきっかけでした。でも、MATLABのすごさが分かったのは、機械学習のオンライン講座で、Andrew Ngが、線型代数を使うと、数式と非常に近い構文のコードで問題が処理できることを学んだ時でした。
Three former MathWorks employees, Steve Wilcockson, David Bergstein, and Gareth Thomas, joined the ArrayCast pod cast to discuss their work on array based languages. At the end of the episode, Steve says,
> It's a little known fact about MATLAB. There's this thing, Gareth has talked about the community. One of the things MATLAB did very, very early was built the MATLAB community, the so-called MATLAB File Exchange, which came about in the early 2000s. And it was where people would share code sets, M files, et cetera. This was long before GitHub came around. This was well ahead of its time. And I think there are other places too, where MATLAB has delivered cultural benefits over and above the kind of core programming and mathematical capabilities too. So, you know, MATLAB Central, File Exchange, very much saw the future.
Listen here: The ArrayCast, Episode 79, May 10, 2024.
