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(Sorry - it should be 2023b by now.)
spy
I'm curious how the community uses the hold command when creating charts and graphics in MATLAB. In short, hold on sets up the axes to add new objects to the axes while hold off sets up the axes to reset when new objects are added.
When you use hold on do you always follow up with hold off? What's your reasoning on this decision?
Can't wait to discuss this here! I'd love to hear from newbies and experts alike!
Calling all students! New to MATLAB or need helpful resources? Check out our MATLAB GitHub for Students repository! Find MATLAB examples, videos, cheat sheets, and more!
Visit the repository here: MATLAB GitHub for Students
Imagine x is a large vector and you want the smallest 10 elements. How might you do it?
The way we've solved ODEs in MATLAB has been relatively unchanged at the user-level for decades. Indeed, I consider ode45 to be as iconic as backslash! There have been a few new solvers in recent years -- ode78 and ode89 for example -- and various things have gotten much faster but if you learned how to solve ODEs in MATLAB in 1997 then your knowledge is still applicable today.
In R2023b, there's a completely new framework for solving ODEs and I love it! You might argue that I'm contractually obliged to love it since I'm a MathWorker but I can assure you this is the real thing!
I wrote it up in a tutorial style on The MATLAB Blog https://blogs.mathworks.com/matlab/2023/10/03/the-new-solution-framework-for-ordinary-differential-equations-odes-in-matlab-r2023b/
The new interface makes a lot of things a much easier to do. Its also setting us up for a future where we'll be able to do some very cool algorithmic stuff behind the scenes.
Let me know what you think of the new functionality and what you think MathWorks should be doing next in the area of ODEs.
To solve the puzzle, first unscramble each of the words on the left. Then rearrange the letters in the yellow shaded boxes to complete the sentence on the right.
If you enjoyed this puzzle let me know with a like or in the comments below and I'll post more of them. Please don't post your answer, or any hints, and spoil it for those who come across this puzzle after you!! If you want to check your answer, you can messge me your guess through the link on my profile card (click on my name, Rena Berman, above and then on the envelope icon in the top right corner of the profile card that appears).
The MATLAB Answers community is an invaluable resource for all MATLAB users, providing selfless assistance and support. However, with the emergence of AI-based chatbots, like chatGPT, there may be concerns about the future relevance and utility of the MATLAB Answer community. What are your thoughts?
I am processing ocean and climate data (1982-2022). Here, I have table which having heatwaves events details. Now, I want to sort the data month wise and also seasonal wise (summer:October- February, and winter:March-September), and then i wanted to plot mean seasonal and trend.
Sample file is attached. length of original file may vary in size.
Thanks in addvance.
This is the 6th installment of the wish-list and bug report thread.
This topic is the follow on to the first Wish-list for MATLAB Answer sections and second MATLAB Answers Wish-list #2 (and bug reports). The third started out as New design of the forum - grey on white and the fourth and fifth also grew so large they are slow to load and navigate.
Same idea as the previous ones: one wish (or bug report) per answer, so that people can vote their wishes.
What should you post where?
Next Gen threads (#1): features that would break compatibility with previous versions, but would be nice to have
@anyone posting a new thread when the last one gets too large (about 50 answers seems a reasonable limit per thread), please update this list in all last threads. (if you don't have editing privileges, just post a comment asking someone to do the edit)
There are two kinds of text data type (=string data type) in MATLAB:
Text1='aText'; % first one
Text2="aText"; % first one
The second one did not exist in "old" MATLAB versions but the first one only.
My questions are: 1) What was motivation of MathWorks programmers to introduce the Text Data Type of the second format?
Yes, I know the difference: length(Text1)=5 whilst length(Text2)=1; Text1(2)='T' but Text2(2) does not exist. The array Text3=['one' ; 'fifth'] does not exist too.
2) However, any explanations and recommendations how to apply the second sort in contrast to the first one?
3) Is there any way how to convert one sort to another one?
Thanks for explanation in advance!
I've now seen linear programming questions pop up on Answers recently, with some common failure modes for linprog that people seem not to understand.
One basic failure mode is an infeasible problem. What does this mean, and can it be resolved?
The most common failure mode seems to be a unbounded problem. What does this mean? How can it be avoided/solved/fixed? Is there some direction I can move where the objective obviously grows without bounds towards +/- inf?
Finally, I also see questions where someone wants the tool to produce all possible solutions.
A truly good exposition about linear programming would probably result in a complete course on the subject, and Aswers is limited in how much I can write (plus I'll only have a finite amount of energy to keep writing.) I'll try to answer each sub-question as separate answers, but if someone else would like to offer their own take, feel free to do so as an answer, since it has been many years for me since I learned linear programming.
Hello,
I am trying to do image to image regression neural network training. In place of digitTrain4DArrayData, I have used my own dataset of 500 input and 500 output grayscale images of size 100*100 pixels for training.
The code is as follows:
imds1 = datastore(fullfile(matlabdrive,"T10itTI"),"IncludeSubFolders",true,...
"FileExtensions",".png","type","image");
imds2 = datastore(fullfile(matlabdrive,"TFiSTI"),"IncludeSubFolders",true,...
"FileExtensions",".png","type","image");
dsnew = combine(imds1,imds2);
layers = [
imageInputLayer([100 100 1])
batchNormalizationLayer
reluLayer('Name','relu_1')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_2')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_3')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_4')
convolution2dLayer(1,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_5')
convolution2dLayer(3,1,'Stride',2)
batchNormalizationLayer
reluLayer('Name','relu_6')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_7')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_8')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_9')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_10')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_11')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_12')
convolution2dLayer(1,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_13')
transposedConv2dLayer(1,1,'Stride',2)
batchNormalizationLayer
reluLayer('Name','relu_14')
convolution2dLayer(1,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_15')
convolution2dLayer(1,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_16')
convolution2dLayer(3,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_17')
convolution2dLayer(1,1,'Stride',1)
batchNormalizationLayer
reluLayer('Name','relu_18')
transposedConv2dLayer(3,1,'Stride',2)
fullyConnectedLayer(1)
regressionLayer
]
lgraph = layerGraph(layers);
options = trainingOptions("adam", ...
InitialLearnRate=8e-3, ...
SquaredGradientDecayFactor=0.99, ...
MaxEpochs=20, ...
MiniBatchSize=64, ...
Plots="training-progress")
net=trainNetwork(dsnew, lgraph, options);
On running the code, I get following error:
Error using trainNetwork Invalid training data. The output size ([1 1 1]) of the last layer does not match the response size ([1 1 1972224]).
When I use fullyConnectedLayer(1972224) in place of fullyConnectedLayer(1), I get following error:
Error using trainNetwork Layer 'fc': Invalid initializer. Requested 1972224x17161 (252.2GB) array exceeds maximum array size preference (5.0GB). This might cause MATLAB to become unresponsive.
Error in mt1tt1 (line 95) net=trainNetwork(dsnew, lgraph, options);
Caused by: Error using nnet.internal.cnn.assembler.InitializeMixin/initializeLearnableParameters Layer 'fc': Invalid initializer. Requested 1972224x17161 (252.2GB) array exceeds maximum array size preference (5.0GB). This might cause MATLAB to become unresponsive.
Can you suggest correction in code?
Thankyou
Hi Fellow Users,
I am Muthuserpi From A begginer of Optics studio Please anyone help me how to add two diffeaction reflective grating and How to tilt and decenter in matlab simulation
Thanks And Regards
S.Muthuserpi
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!
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.
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:
struct_array.field % all elements
struct_array(idx).field % selected elements
cell_array{:} % all elements
cell_array{idx} % selected elements
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:
Click on these links to jump to relevant comments below:
Dynamic Indexing (indexing into arrays with arbitrary numbers of dimensions)
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)
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
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:
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