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David
David
最後のアクティビティ: 2020 年 2 月 12 日

January 2020 release notes

The following is a list of updates and new features for MATLAB Central, including MATLAB Answers, File Exchange, Blogs, and Cody.

New Features

Profile search - A global community profile search has been added. The search field on community profile pages has been updated from a standard content search to a user profile search. This improvement makes it easier to find community members across all MATLAB Central. Previously one had to search the Answers contributors , File Exchange authors , and Cody players page when looking for a user profile.

Last seen - We have added a 'last seen' timestamp to community profiles which displays the date of a person's last visit to MATLAB Central. This can be a relevant bit of information and help determine how recent someone has been active in the community.

Answers pages design update - Answers Q&A pages have been updated to remove extra white space. This update includes smaller sized avatars, and position changes for the voting and content actions among other small changes. All these changes also help improve the mobile experience as well.

Original poster styles - Original poster styles have been introduced in Answers. When a question author participates in a Q&A thread their comments or answers will be styled with a blue background and left border so they're easily discernable from other contributors.

File Exchange data in monthly emails - File Exchange stats will be included in the monthly email we send to contributors who've participated in the community on any given month.

Trending content algorithm - The MATLAB Central home page trending content algorithm has been updated to look at content activity over a shorter period of time resulting in a more dynamic feed.

Walter Roberson does it again by winning the coveted MOST ACCEPTED answers badge for all his contributions in MATLAB Answers this past year. Walter has won this badge every year since 2015. It was way back in 2014 when Image Analyst out paced Walter and was awarded the badge.

There are 10 community members who have achieved the Top Downloads badge for their popular File Exchange submissions in 2019. Do you recognize any of these names? There's a good chance you've used one or more of their toolboxes or scripts in your work if you're a frequent visitor to File Exchange, if you're not you might want to check out what they've posted, it may save you a lot of time writing your own code.

--------------------- Top Downloads Badge Winners -----------------

Congratulations to all these winners and a giant THANK YOU for all they've done this past year to help everyone in the MATLAB Central community!

David
David
最後のアクティビティ: 2020 年 1 月 21 日

Introducing File Exchange badges

We are happy to announce that virtual badges can now be achieved for participating in MATLAB Central File Exchange . We have 30 badges that anyone can achieve, which will also boost your community profile. Some badges are relatively simple to get while others will depend on how useful your submissions are to others in the community. Check out Ned Gulley's blog post for a great introduction.

David
David
最後のアクティビティ: 2020 年 1 月 21 日

Introducing the new Power Electronics Control community

Explore resources, ask questions, and discuss topics related to using Simulink to apply power electronics control to Electric Vehicles, Renewable Energy, Battery Systems, Power Conversion, and Motor Control. This is the 3rd MATLAB Central community, after Maker and SimBiology , and is moderated by Tony Lennon . Tony is the Power Electronics Marketing Manager at MathWorks.

Visit the community here . As always, let us know what you think by liking this post or commenting below.

Rik
Rik
最後のアクティビティ: 2022 年 11 月 4 日

How to create a GUI

There are multiple ways to create a graphical user interface (GUI) in Matlab. Which method is the best depends on multiple factors: the complexity of the project, to what extent it should be a long-term solution, on what releases your GUI should work, your available time, your skill level, and probably other factors I'm forgetting.
To keep the thread clear I'll attempt to provide a short outline a few ways in this question, and leave the details for the answers. (@anyone with editing privileges: feel free to update the section below if I missed something important and am slow in editing this question)
---------------------------------------------------------------------------------------------------
GUIDE
GUIDE is probably the first tool new users will encounter. It is very useful for quickly putting something together, but it is otherwise fairly limited. It requires maintaining (and distributing) both a .m and a .fig file. Note that the GUIDE environment will be removed in a future release. After GUIDE is removed, existing GUIDE apps will continue to run in Matlab but they will not be editable in GUIDE. If you're starting a new GUI, don't use GUIDE. If you're updating an existing GUIDE GUI, migrate it to AppDesigner. In R2021a the first step for this removal was taken: all templates except the blank template have been removed.
GUILT
Although I haven't had a detailed look myself, it seems a list like this is not complete without at least mentioning the GUI Layout Toolbox, which is available on the file exchange and offers a lot of customization options.
Programmatic GUIs
You can bypass GUIDE and use the normal figures and functions like uicontrol to build GUIs from code. This makes the design less visual, but more flexible for future additions.
App Designer
The official successor to GUIDE, AppDesigner is not based on functions, but works similar to a class. It uses uifigure and mostly uses graphical elements that are incompatible with 'normal' GUIs that are created with a figure (or .fig).
Stephen23
Stephen23
最後のアクティビティ: 2024 年 4 月 10 日

TUTORIAL: Why Variables Should Not Be Named Dynamically (eval)

Summary:
Dynamically accessing variable names can negatively impact the readability of your code and can cause it to run slower by preventing MATLAB from optimizing it as well as it could if you used alternate techniques. The most common alternative is to use simple and efficient indexing.
Explanation:
Sometimes beginners (and some self-taught professors) think it would be a good idea to dynamically create or access variable names, the variables are often named something like these:
  • matrix1, matrix2, matrix3, matrix4, ...
  • test_20kmh, test_50kmh, test_80kmh, ...
  • nameA, nameB, nameC, nameD,...
Good reasons why dynamic variable names should be avoided:
There are much better alternatives to accessing dynamic variable names:
Note that avoiding eval (and assignin, etc.) is not some esoteric MATLAB restriction, it also applies to many other programming languages as well:
MATLAB Documentation:
If you are not interested in reading the answers below then at least read MATLAB's own documentation on this topic Alternatives to the eval Function, which states "A frequent use of the eval function is to create sets of variables such as A1, A2, ..., An, but this approach does not use the array processing power of MATLAB and is not recommended. The preferred method is to store related data in a single array." Data in a single array can be accessed very efficiently using indexing.
Note that all of these problems and disadvantages also apply to functions load (without an output variable), assignin, evalin, and evalc, and the MATLAB documentation explicitly recommends to "Avoid functions such as eval, evalc, evalin, and feval(fname)".
The official MATLAB blogs explain why eval should be avoided, the better alternatives to eval, and clearly recommend against magically creating variables. Using eval comes out at position number one on this list of Top 10 MATLAB Code Practices That Make Me Cry. Experienced MATLAB users recommend avoiding using eval for trivial code, and have written extensively on this topic.
The community is very helpful, yet I feel really powerless that I cannot find the appropriate way to code, nor find the problems with the codes I have written. I have read numerous books on MATLAB, mostly related with science and engineering applications. Any advice to improve would be greatly appreciated. Thanks.
Raviteja
Raviteja
最後のアクティビティ: 2012 年 1 月 27 日

Good programming practice...

Hello all,
Please explain good MATLAB programming practice methods. It will help to the guys who are new to programming like me.
Previously I used
for i=1:10
after following some suggestions from this answers pages I learnt to use
for i1=1:100
This is the good way to write programs.
Like this, as a professional programmer, please mention some good programming practice techniques.
It will useful to all!
Oleg Komarov
Oleg Komarov
最後のアクティビティ: 2021 年 12 月 9 日

Greek alphabet and latex commands [not a question]

Capital letters are obtained by capitalizing the LaTeX command for the lowercase version. Capital letters in grey are exceptions which have no LaTeX commands. For example, to produce a capital chi simply type X (this also applies for the lowercase omicron).
When two versions of the lowercase letter are available, a var prefix can be added to obtain the second version. For example, the two versions of epsilon are \epsilon and \varepsilon.
--------------------------------------------------------------------------------------------------------------------------------------------------------
The code used to generate the table:
greeks = ...
{'ALPHA' 'A' '\alpha'
'BETA' 'B' '\beta'
'GAMMA' '\Gamma' '\gamma'
'DELTA' '\Delta' '\delta'
'EPSILON' 'E' {'\epsilon','\varepsilon'}
'ZETA' 'Z' '\zeta'
'ETA' 'H' '\eta'
'THETA' '\Theta' {'\theta','\vartheta'}
'IOTA' 'I' '\iota'
'KAPPA' 'K' '\kappa'
'LAMBDA' '\Lambda' '\lambda'
'MU' 'M' '\mu'
'NU' 'N' '\nu'
'XI' '\Xi' '\xi'
'OMICRON' 'O' 'o'
'PI' '\Pi' {'\pi','\varpi'}
'RHO' 'P' {'\rho','\varrho'}
'SIGMA' '\Sigma' {'\sigma','\varsigma'}
'TAU' 'T' '\tau'
'UPSILON' '\Upsilon' '\upsilon'
'PHI' '\Phi' {'\phi','\varphi'}
'CHI' 'X' '\chi'
'PSI' '\Psi' '\psi'
'OMEGA' '\Omega' '\omega'};
h = figure('units','pixels','pos',[300,100,620,620],'Color','w');
axes('units','pixels','pos',[10,10,600,600],'Xcol','w','Ycol','w',...
'Xtick',[],'Ytick',[],'Xlim',[0 6],'Ylim',[0,4]);
% Loop by column and row
for r = 1:4
for c = 1:6
el = (r-1)*6 + c;
% Title
text(c-0.5,5-r,greeks{el,1},'Fonts',14,'FontN','FixedWidth',...
'Hor','center','Ver','cap')
% Color cap latter in grey or black
if strcmp(greeks{el,2}(1),'\')
clr = [0, 0, 0];
else
clr = [0.65, 0.65, 0.65];
end
% Cap letter
text(c-0.5,4.87-r,['$\rm{' greeks{el,2} '}$'],'Fonts',40,...
'Hor','center','Ver','cap','Interp','Latex','Color',clr)
% Lowercase letter/s (if two variants)
if iscell(greeks{el,3})
text(c-0.75,4.48-r,['$' greeks{el,3}{1} '$'],'Fonts',20,...
'Hor','center','Interp','Latex')
text(c-0.25,4.48-r,['$' greeks{el,3}{2} '$'],'Fonts',20,...
'Hor','center','Interp','Latex')
% Latex command
text(c-0.5,4.3-r,['\' greeks{el,3}{1}],'Fonts',12,'FontN','FixedWidth',...
'Hor','center','Ver','base')
else
text(c-0.5,4.48-r,['$' greeks{el,3} '$'],'Fonts',20,...
'Hor','center','Interp','Latex')
text(c-0.5,4.3-r,['\' greeks{el,3}],'Fonts',12,'FontN','FixedWidth',...
'Hor','center','Ver','base')
end
end
end
% Print to pdf
export_fig greeks.pdf
The link to export_fig.
And here is the link to the pdf on scribd: http://www.scribd.com/doc/159011120/Greek-alphabet-in-latex
Oleg Komarov
Oleg Komarov
最後のアクティビティ: 2023 年 3 月 8 日

TUTORIAL: how to format your question with markup

[INDEX]
--------------------------------------------------------------------------------------------------------------------------------------
[MOTIVATION]
Why should we use markups in the body of our questions?
The answer is a question: which of the two versions is more likely to be understood in a glimpse and has more chances to be answered by our readers?
.
< Consider the following question >
I have a vector of weights W=[10,20,30,50,23434,1,2.4,2] and a matrix A=rand(100,8) and I would like to find the row-wise weighted sum of A. I am proceeding in the following way: B=zeros(size(A)); for c=1:numel(W) B(:,c)=A(:,c)*W(c); end B=sum(B,2); Somehow I get huge numbers can you please help?
.
< Now, consider its formatted version >
I have a vector of weights W = [10,20,30,50,23434,1,2.4,2] and a matrix A = rand(100,8) and I would like to find the row-wise weighted sum of A.
I am proceeding in the following way:
B = zeros(size(A));
for c = 1:numel(W)
B(:,c) = A(:,c)*W(c);
end
B = sum(B,2);
Somehow I get huge numbers can you please help?
--------------------------------------------------------------------------------------------------------------------------------------
[AKNOWLEDGMENTS]
In alphabetical order by nickname, thanks for their suggestions to:
Walter Roberson
--------------------------------------------------------------------------------------------------------------------------------------
[LOG]
  • 06 Aug 2011, 13:17 BST - created and added boldface.gif
  • 06 Aug 2011, 14:59 BST - added italic.gif
  • 06 Aug 2011, 18:58 BST - added index section
  • 07 Aug 2011, 00:03 BST - added code.gif and tutorial series section
  • 07 Aug 2011, 01:50 BST - added monospaced.gif, numlist.gif, bullist.gif and hyperlink.gif
  • 13 Aug 2011, 14:27 BST - added motivation section
  • 18 Aug 2011, 01:44 BST - added aknowledgments section and link to wish-list
--------------------------------------------------------------------------------------------------------------------------------------
[TUTORIAL Series]
Do not forget to read the Markup help (located on the top-right corner of the Body pane)
Vote on Wish-list for MATLAB Answer sections my post if you think that a tutorial section on top of Answers could be useful.
Jason
Jason
最後のアクティビティ: 2020 年 12 月 16 日

Best way(s) to master MATLAB?

Now, I am still a novice when it comes to programming. I believe MATLAB is definitely a great programming tool, one that I can play with, particularly, when I have free time.
I would love to hear from all answerers, what are the ways that can make one proficient in this field?
amit jain
amit jain
最後のアクティビティ: 2023 年 6 月 2 日

How to learn MATLAB

What is the best way to learn MATLAB at home without a tutor?