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Graham Dudgeon
Graham Dudgeon
最後のアクティビティ: 2022 年 5 月 5 日

New MathWorks Video explaining Complex Power available on YouTube

Hullo Everyone. I have published a video on the MathWorks YouTube channel that explains active, reactive and apparent power. It is less than 9 minutes and so can be viewed over a coffee break. Here's the link https://www.youtube.com/watch?v=DCUwK6AfzcM
Hi,
I am using matlab fuction block to calculate duty ratio for a MOSFET . How do I incorporate time delay in the calculated duty cycle. Duty cycle of S3 should be delayed by d1 in the picture.Kindly help

I have a datasheet of an induction motor (as figure below). I want to simulate it on matlab/simulink, but I don't know it's parameters (Lls, Llr, Lm, Rr, Rs).

I tried to search about open circuit test and blocked rotor test to determine these parameters, but some of information doesn't appear on datasheet and I don't have the real motor to test on it (datasheet is only think I have).

Could someone help me with this?

Aycan Hacioglu
Aycan Hacioglu
最後のアクティビティ: 2022 年 3 月 28 日

Keeping students engaged with MATLAB competitions using MATLAB Grader

Assignments, quizzes, midterms, finals, grades, joys of success, the anxiety of low grades. Sounds like a typical cycle that students go through, right? Sometimes, all that hustle and bustle makes students forget that coding could be fun! Dr. Amin Rahman teaches AMATH 301 at the University of Washington. Many engineering students take this course and learn MATLAB in the course. He was looking for ways to keep students engaged and remind them that coding is fun. To achieve this goal Dr. Rahman and I set up a small competition in MATLAB Grader. Dr. Rahman selected several problems from MATLAB Grader problem collections. Students competed in this optional competition without the pressure of grades. They submitted their solutions; their submissions were automatically graded using MATLAB Grader and they got instant feedback. Green checkmarks for the correct answers empowered students and gamified coding. With the feedback they got, they continuously improved their code.

Prizes? Aside from the joys of coding in MATLAB, students won MathWorks-branded items like t-shirts, hats, and bags and proudly wore them as you can see in Dr. Rahman’s tweet.

Interested in using MATLAB Grader? Interested in accessing MATLAB Grader problem collections? Like to brainstorm ideas to make coding more fun? Reach out to us! We are here to help. Any creative ideas to make courses more engaging? Please share your ideas with this community!

Antonello Zito
Antonello Zito
最後のアクティビティ: 2025 年 1 月 13 日 22:38

Mathworks: it's time for a dark theme.

This is not a question, but a point of discussion for the entire community. I am aware that every 1/2 months this theme comes out, but until this is not fixed it is totally necessary that this comes, indeed, out. And I said "fix" because Mathworks has to understand that a dark theme is not only a visual/aesthetic matter, it is a substantial part of the game. Most of the OS, GUIs, programs are actually in dark mode, and a vast majority of the users makes indeed use of a global dark mode. How much one does like it is personal, but the benefits to power savings and eye health is instead a fact. Mathworks being ignoring this for years is nothing but ridiculous. Of course it is not an easy task, but every minute of committment for it is worthy. And nope, Schemer is not helpful because it does not provide a real fix to this question.
I feel free to suggest something similar to the Spyder's dark theme, which came out like 2 years ago if I remember correctly.
Of course, my point is not being disrespectful (I am instead very respectful to the huge efforts of Mathworks for making this wonderful program run). But, form a user's point of view, the fact that not a single word has so far come out from Mathworks about a dark theme (meaning that for sure we will not see it in a timing of months) requires us to put a strong pressure on this.
Mathworks, please: it's time for a dark theme.
Stephen23
Stephen23
最後のアクティビティ: 2024 年 4 月 12 日

TUTORIAL: Comma-Separated Lists and How to Use Them

Introduction
Comma-separated lists are really very simple. You use them all the time. Here is one:
a,b,c,d
That is a comma-separated list containing four variables, the variables a, b, c, and d. Every time you write a list separated by commas then you are writing a comma-separated list. Most commonly you would write a comma-separated list as inputs when calling a function:
fun(a,b,c,d)
or as arguments to the concatenation operator or cell construction operator:
[a,b,c,d]
{a,b,c,d}
or as function outputs:
[a,b,c,d] = fun();
It is very important to understand that in general a comma-separated list is NOT one variable (but it could be). However, sometimes it is useful to create a comma-separated list from one variable (or define one variable from a comma-separated list), and MATLAB has several ways of doing this from various container array types:
1) from a field of a structure array using dot-indexing:
struct_array.field % all elements
struct_array(idx).field % selected elements
2) from a cell array using curly-braces:
cell_array{:} % all elements
cell_array{idx} % selected elements
3) from a string array using curly-braces:
string_array{:} % all elements
string_array{idx} % selected elements
Note that in all cases, the comma-separated list consists of the content of the container array, not subsets (or "slices") of the container array itself (use parentheses to "slice" any array). In other words, they will be equivalent to writing this comma-separated list of the container array content:
content1, content2, content3, .. , contentN
and will return as many content arrays as the original container array has elements (or that you select using indexing, in the requested order). A comma-separated list of one element is just one array, but in general there can be any number of separate arrays in the comma-separated list (zero, one, two, three, four, or more). Here is an example showing that a comma-separated list generated from the content of a cell array is the same as a comma-separated list written explicitly:
>> C = {1,0,Inf};
>> C{:}
ans =
1
ans =
0
ans =
Inf
>> 1,0,Inf
ans =
1
ans =
0
ans =
Inf
How to Use Comma-Separated Lists
Function Inputs: Remember that every time you call a function with multiple input arguments you are using a comma-separated list:
fun(a,b,c,d)
and this is exactly why they are useful: because you can specify the arguments for a function or operator without knowing anything about the arguments (even how many there are). Using the example cell array from above:
>> vertcat(C{:})
ans =
1
0
Inf
which, as we should know by now, is exactly equivalent to writing the same comma-separated list directly into the function call:
>> vertcat(1,0,Inf)
ans =
1
0
Inf
How can we use this? Commonly these are used to generate vectors of values from a structure or cell array, e.g. to concatenate the filenames which are in the output structure of dir:
S = dir(..);
F = {S.name}
which is simply equivalent to
F = {S(1).name, S(2).name, S(3).name, .. , S(end).name}
Or, consider a function with multiple optional input arguments:
opt = {'HeaderLines',2, 'Delimiter',',', 'CollectOutputs',true);
fid = fopen(..);
C = textscan(fid,'%f%f',opt{:});
fclose(fid);
Note how we can pass the optional arguments as a comma-separated list. Remember how a comma-separated list is equivalent to writing var1,var2,var3,..., then the above example is really just this:
C = textscan(fid,'%f%f', 'HeaderLines',2, 'Delimiter',',', 'CollectOutputs',true)
with the added advantage that we can specify all of the optional arguments elsewhere and handle them as one cell array (e.g. as a function input, or at the top of the file). Or we could select which options we want simply by using indexing on that cell array. Note that varargin and varargout can also be useful here.
Function Outputs: In much the same way that the input arguments can be specified, so can an arbitrary number of output arguments. This is commonly used for functions which return a variable number of output arguments, specifically ind2sub and gradient and ndgrid. For example we can easily get all outputs of ndgrid, for any number of inputs (in this example three inputs and three outputs, determined by the number of elements in the cell array):
C = {1:3,4:7,8:9};
[C{:}] = ndgrid(C{:});
which is thus equivalent to:
[C{1},C{2},C{3}] = ndgrid(C{1},C{2},C{3});
Further Topics:
MATLAB documentation:
https://www.mathworks.com/help/matlab/matlab_prog/comma-separated-lists.html
https://www.mathworks.com/help/matlab/matlab_prog/access-multiple-elements-of-a-nonscalar-struct-array.html
https://www.mathworks.com/company/newsletters/articles/matlab-tips-and-tricks-exploiting-the-comma-separated-list-vectorizing-cell-array-and-structure-references.html
Click on these links to jump to relevant comments below:
Dynamic Indexing (indexing into arrays with arbitrary numbers of dimensions)
Nested Structures (why you get an error trying to index into a comma-separated list)
Summary
Just remember that in general a comma-separated list is not one variable (although they can be), and that they are exactly what they say: a list (of arrays) separated with commas. You use them all the time without even realizing it, every time you write this:
fun(a,b,c,d)
Reza Fazel-Rezai
Reza Fazel-Rezai
最後のアクティビティ: 2022 年 2 月 18 日

Live Script Lecture Notes - Advanced MATLAB for Scientific Computing

If you are interested in live script lecture notes in the following areas, take a look at the short course ( Advanced MATLAB for Scientific Computing ) developed at Stanford. You can also download the required data for the examples from the course GitHub page.

  • MATLAB Fundamentals
  • Graphics and Data Visualization
  • Efficient Code Writing
  • System and File Manipulation
  • Big Data Handling
  • Numerical Linear Algebra
  • Numerical Optimization
  • Symbolic Toolbox, ODE, and PDE
  • Statistical and Machine Learning
  • Deep Learning
  • Object-Oriented Programming
  • Using MATLAB with Other Programming Languages
  • Image Processing, Computer Vision, and Image Acquisition
  • Signal Processing, Audio, and DSP System
Aycan Hacioglu
Aycan Hacioglu
最後のアクティビティ: 2022 年 2 月 11 日

Teaching MATLAB and Python side by side online or in-person

In many universities, introductory programming is taught as a foundation course. Students from different departments are usually brought together to learn to program in these foundation courses. Their home departments may have a programming language preference and that preference may change from department to department. Some universities either strictly teach one language in a single course, some of them teach multiple languages in the same course and give students the flexibility to choose their language for the assignments and projects. How can we make students multilingual when it comes to programming? Is there a way to teach multiple languages in a fair light, side by side without creating a new course or sacrificing one language to teach the other one? Dr. Nathan Kutz from the University of Washington found a creative way to teach MATLAB and Python side by side in his AMATH 301 course. This course is an introductory programming course at the University of Washington and almost all engineering students take it. Do you wonder how Dr. Kutz taught this course? Check out these recordings and course resources! They can be utilized in an in-person or a distance learning setting:

Are you looking for ways to keep your students engaged in a virtual setting? Would you like to spice up your courses with hands-on projects? Using Arduino Engineering Kit, you can achieve these. Due to COVID-19, many instructors started to look for creative ways of giving students a lab experience. Some of them chose to create virtual labs, some of them designed hardware projects with low-cost hardware or integrated hardware projects kits to their curriculum. If you are interested in how Dr. Azadi from San Francisco State University used Arduino Engineering Kit during the pandemic to teach his Mechatronics course, check out these articles:

Roberto Carabajal
Roberto Carabajal
最後のアクティビティ: 2022 年 1 月 27 日

Brushless motor Simulink model

I need to model a brushless motor for which I only have the data of voltage, power, speed, nominal torque, starting torque, max current and total weight, which moves a bicycle. I have studied the Permanent Magnet Synchronous Machine power_pmmotor Simulink example, but I do not have all the required data. My question is whether it is possible to make an approximate model with my few data. I guess some data could be assumed, but I don't know what typical values ​​would be correct. I would greatly appreciate any suggestion. My best regards.

Mannika Garg
Mannika Garg
最後のアクティビティ: 2021 年 12 月 28 日

Detailed Tutorial for Battery Modelling

Hi,

I am new to Matlab and looking to model complete EPS system starting with battery modelling. I have seen videos where the modelling is explained but looking for a one which can teach me from the scratch.

Hi, currently I'm studying about DC-DC Boost converter with controller. After I applied the step time, the output voltage supposed to follow the step time, but there is some delay in the simulation results after I applied the "step time" in the step input block. Can someone help, why this delay occur? Please see the attached pictures. Thanks

Dr Narayanaswamy P R Iyer
Dr Narayanaswamy P R Iyer
最後のアクティビティ: 2021 年 11 月 23 日

switching power supply made by VIPER22A scheme

As per data sheet for VIPER22A, the product is obsolete.

Dr Narayanaswamy P R Iyer
Dr Narayanaswamy P R Iyer
最後のアクティビティ: 2021 年 11 月 23 日

water buffalo PC150NCA

For UC3843A you will have to refer to the data sheet, link given below: https://www.ti.com/lit/ds/symlink/uc3843a.pdf?ts=1637624394197&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FUC3843A

For UC3843A, the reference output voltage is 5 V and the normal output voltage is 13.5 V.

Rose Li
Rose Li
最後のアクティビティ: 2021 年 11 月 20 日

Is the power block UC3843A the same as UC3843B?

After repairing the power supply of a big water buffalo PC150NCA, now all the parts found to be broken are replaced, but the power-on output 12V is only 4.2V. The original power supply block is UC3843B, which is not sold locally. I can only buy a UC3843A replacement . I don’t know if the low output voltage has anything to do with this (the optocoupler and the 431 voltage regulator block have also been replaced)

Steve Schaefer
Steve Schaefer
最後のアクティビティ: 2021 年 11 月 22 日

Physical Modelling for Virtual Hardware and Labs

Attention all Controls Professors, Teaching Assistants, and Students!

The Virtual Hardware and Labs for Controls by Brian Hong is an absolute must-have from the MATLAB Central File Exchange. With the help of Simscape for physical modelling and simulation of mechatronic systems,

  • students can use the interactive experiments to teach themselves some of the concepts of control theory in a learn by doing approach.
  • professors and TA’s can use this to replace or augment actual lab work.

With tightening budgets and/or in person class restrictions this can help you transfer these vital skills to the students in a fun manner. Here is an overview of the available modules:

https://www.mathworks.com/matlabcentral/fileexchange/100064-virtual-hardware-and-labs-for-controls

If you have any questions feel free to leave a comment below and I’ll get back to you.

Sumit Tandon
Sumit Tandon
最後のアクティビティ: 2021 年 11 月 17 日

Virtual Labs in Electric Circuits

Hi DLC, in case you haven't seen it already, Dr. Dennis Dahlquist and Dr. Zekeriya Aliyazicioglu recently developed a collection of Virtual Labs in Electric Circuits . Please feel free to explore and share your thoughts!

Chen Lin
Chen Lin
最後のアクティビティ: 2021 年 12 月 17 日

Please let us know your experience on MATLAB Central 20th Anniversary contests!

In the past 2 months, we had a lot of fun together playing in the two contests. 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. Thank you in advance and hope to see you in 2022!

Rose Li
Rose Li
最後のアクティビティ: 2021 年 11 月 11 日

How to change？

With the switching power supply made by VIPER22A scheme , the 5V output always has noise, and the ripple exceeds 200MV after loading. How to change it? 1. 220VAC input, two outputs, 24V and 5V output are noisy, the ripple after 5V load is more than 200MV, 5V is connected with an LDO to 3.3V, and the measured 3.3V is also noisy, and the LDO heats up seriously. Change The LDO remains unchanged. 2. It is suspected that the load current is large, but I changed a circuit board with the same scheme and found that there is no noise. Although there are ripples, it is not very hot. 3. In addition, directly use a 5V adapter to convert to 3.3V through the same LDO. problem. How to change the device in this figure? 4. For hardware novices, the transformer will not be changed temporarily, and I hope to improve it by adjusting other devices.

After 7 weeks of fun, the MATLAB Central community 20th anniversary contests have concluded! Together, we shared the art of MATLAB and contributed to the battle against the global pandemic. See the fantastic stats below.

MATLAB Mini Hack Winners - Week 4

In Week 4, we invited the MATLAB Graphics team to help judge the entries. As the authors of the MATLAB functions used in every entry, they made sure every entry selected used a unique graphics function or technique from the other winners. Here are their choices:

1. Umbrellas by Shanshan Wang

Comment: Cool use of 'swarmchart' to make art from distributions; Only use of one of our newest graphics functions

2. Happy Sheep by Victoria

Comment: Cute!

3. Alien Giant by Jenny Bosten

Comment: Original idea, well textured, and efficient code

4. 3D Ultrasound by Adam Danz

Comment: Replicate source material very well. Effective use of lighting and material. Overall, impressive to produce this image given the limitation

5. Sunset in the Savanna by Sebastian Kraemer

Comment: Looks cool! Nice mix of 'image', 'fill' and 'scatter' commands.

6. Night Flight by Ratul Das

Comment: original; clever use of 'rectangle'

7. Lantern #2 by Tim

Comment: Nice use of 'getframe' to create a texture for 'surf' for a compelling picture

8. Geometric Design (6) by Daniel Pereira

Comment: Looks like some walls at MathWorks

9. Rosette 1313 by Alex P

Comment: Looks cool! Nice use of 'pcolor'

10. Mandelbrot contour by Sumihiro

Comment: Best use of contour!

11. Aim High by Murty PLN

Comment: Largest number of unique graphics objects for the Mini Hack (plot, patch,stairs,stem,text)

In the spirit of Mini Hack, the MATLAB Graphics team also created several cool graphs about the contest. Facing a similar space limit, I have picked only 2.

Bonus Prize Winners - Week 4

Congratulations to our 5 winners for their dual participation in the Treasure Hunt and the MATLAB Mini Hack. Yogiraj Bhagavatula, Pramod Devireddy, Devika U, FruitsLord, and Augusto Mazzei.

Lucky voters - Week 4

Congratulations to the lucky voters who cast the 12000th vote (Gordg Garin), 12500th vote (Eder Esteban Reyes), 13000th vote (Peram Balakrishna), 13500th vote (Emerson Nithiyaraj), 14000th vote(Sekar Naai), 14500th vote (Arika Amasarao), 15000th vote (Nikita Yakovlev), 15500th vote (Kesava Rao), and 16000th vote (Kundi Chandra Sekhar).

Grant Prize Winners

Finally, after validating entries and votes, we have picked the grand prize winners. We appreciate the time and effort you spent and the awesome entries you created. Huge congratulations!

1. Top 10 Authors of most voted entries

Each author will receive 5 customized T-shirts with the winning image and your name on the back of the T-shirts. You can choose the sizes and share them with your family or friends.

2. Top 10 Authors with most total votes

Top 10 contestants on the leaderboard will each get an Amazon gift card. The top 3 winners on the leaderboard will also earn special virtual badges.

  • Ciro Bermudez
  • KSSV
  • Juan Villacrés
  • Murty PLN
  • Pink_panther
  • Jenny Bosten
  • KARUPPASAMYPANDIYAN M
  • Jr
  • Adam Danz
  • Victoria

On behalf of the MATLAB Central community team, we thank you for joining our celebration of the MATLAB Central community’s 20th anniversary with us in the past 7 weeks. We hope you enjoyed these contests and look forward to seeing you in next year’s contests. Question: “What contests would you like to see next?”