How do I get help on homework questions on MATLAB Answers?

There are many students that come to MATLAB Answers looking for help with their homework. Some students make their question interesting and of use to other people (other people not in their class, that is) and they are responded to quickly. Some students copy and paste their question with little apparent effort. They are often ignored.

A related question is:

How does someone ask a good question?

However, I would like to have an answer specifically targeted to struggling students.

Please do not post your homework questions in this discussion thread!

[hisyam mudin]

[hisyam mudin]

how to solve this question with matlab??

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer

[jonas]

@hisyam: Your question would've been amusing if it wasn't for the fact that it was posted unironically. Please take some time to read the answers in this thread :)

[Akhil Sunny]

Generate two separate sinusoid signals as follows: x1(t) = 100 sin(2π101.56t) x2(t) = 2 sin(2π156.25t) Use a sampling frequency of 1 kHz and signal length of 64 ?

what does it mean by signal length and how solve it

Answer 1

[Matt Fig]

MATLAB Answers is a place you can get help from the user community on specific MATLAB questions. It is not intended as a place to have strangers do your homework for you.

Desiring help with homework is fine, but:

• show what you have done so far (post some code and explain what you are thinking about how to solve the problem).
• ask a specific question about either specific MATLAB syntax/constructs, or general guidance (such as "what functions should I look at to achieve [result]")
• make sure your question is answerable. A non-answerable question looks like, "How can I use MATLAB for Image Processing."

If you need help with the very basics of MATLAB, please read the getting started documentation.

[Matt Fig]

Adapted from a post by Matt Tearle.

[Sean de Wolski]

Show respect: don't say urgent and spell "please" correctly.

[Simon]

Be patient! Don't post your question every hour with a new title if you didn't receive an answer.

Answer 2

[Jan]

• Consider, that your teacher or assistent knows MATLAB Answers, too. A copy of her or his question does not cause amusement. A copy of an answer is cheating.
• The community either spend hours to assist you, or seconds to ignore your question. So read your own question and estimate if it catchs the attention and contain enough information for a meaningful answer.
• Do not send question by email. Answering in this public forum is a leisure activity, answering emails is work.

Answer 3

[Walter Roberson]

I wrote the following to someone in email few months ago; feel free to adapt as appropriate:

=================

The people who answer questions here are all volunteers. Your best strategy for getting assistance from them is to make your question as easy and enjoyable to answer as you can.

Making your question as easy to answer as possible includes asking specific questions, and posting specific error messages you have encountered, and indicating the line you encountered the problem on, and includes you doing some elementary debugging such as determining (and posting) the size and data class of the variables involved.

Making the question as enjoyable to answer as possible is more subtle, as different things appeal to different people.

Long experience has shown that giving students complete code for a complex topic seldom works well: frequently, what the student "learns" from the interaction is that other people will do their homework or project for them, giving them an advantage that others did not have.

It is in the interest of society that students learn how to ask good questions and how to cooperate with others, and learn how to learn, and how to manage their time well. The ability to learn and work with society is more important in many ways than that the student grasp everything immediately or get the highest marks -- a good student will keep on learning after they graduate and will come to understand more things in time.

The other side of this is that it is in the interest of society that students who are unable to do learn to ask good questions or work with others, or who do not show an clear interest in learning, do not graduate. For example, a candidate Engineer who copies an important assignment on Loading and Bearing is a menace to society, as society trusts Engineers to be competent at what they claim to know.

A solo final year project is a test of your ability to do research and work things through from theory. Having a completed example of your project before you will not help you in those -- and would tend to strongly direct you towards the way of thinking of the person who wrote the example, rather than encouraging you to innovate and find ways to put ideas together. If you are not able to research and innovate and require a completed example to work from, then it is better for yourself and society that you withdraw from the course and obtain a degree or diploma that reflects what you are capable of.

It is thus inadvisable to suggest that people who are hinting that you are taking the wrong approach should say nothing: such people are giving you valuable advice on "how to play the game", and learning how to interact with an environment can be more valuable than the answer to any one question.

[Bjorn Gustavsson]

To the end of the second paragraph one could add: Isolating and exposing the error is beneficial in several ways: 1, You might actually find the error or bug yourself! 2, You show that you have seriously tried to find the bug or error yourself, increasing the possibility to get someone to try to help.

Answer 4

[Doug Hull]

I learned MATLAB by doing my MATLAB homework. I know how to debug, architect code, and solve problems because I have failed at doing these things MANY, MANY times. I still do.

Of all the things I learned in college, MATLAB has by far been the most valuable (economically and in general). Every job I have gotten since I was a junior in college I have gotten almost entirely because I knew MATLAB better than most of the people in my ever increasing applicant pool.

There is a difference between seeking help and "outsourcing your homework". If you ask a homework question,

• Show what you have done
• Link to wikipedia about any concept we might not know about
• Do not just paste a bunch of code, shorten it to the small bit that is giving the error. Most MATLAB errors can be reproduced in a few lines.
• Your problem is urgent to you. It is not urgent to us. Putting "urgent!!!!" on the question, counterintuitively, tells us to ignore it.
• We will not e-mail you directly, don't ask.

Struggle with the homework, ask your professor. Getting a good relationship with your professors starts with seeing them in their office. My first research gig, my job tutoring a professor in MATLAB, my first book contract all came from relationships with professors. I still make it a point to call several of them once a year.

They are a great place to find new hires for The MathWorks. When I call them up to ask for the resumes of the newest crop of MATLAB geniuses, they are going to think about the people that are in their office talking MATLAB with them. Be that person.

What I am trying to say, is there is more at stake than finishing this one assignment here. Do yourself a favor, struggle and fail at your MATLAB programming. You will come out stronger for it.

[Harsha Vardhan Rao Avunoori]

@Doug...Exactly this is working for me.The more I fail in programming the more I am learning.Thanks Mathworks for creating this wonderful Answers forum :)

[Rik]

One of the thing I told my pupils/fellow students when teaching a crash course Matlab is that you don't make less errors when you get better, you're just faster and better at spotting them. (and the type of error you make changes of course)

Answer 5

[Sean de Wolski]

Do not copy and paste the assignment.

Summarize it in your own words tuned to your specific question.

Answer 6

[Sudipta Dutta]

Write a function called tri_area that returns the area of a triangle with base b and height h, where b and h are input arguments of the function in that order.

[madhan ravi]

You must be joking right xd

[Walter Roberson]

``You are sad'', the Knight said in an anxious tone: ``let me write you a function to comfort you.''

``Is it very long?'' Alice asked, for she had read a good deal of code that day.

``It's long,'' said the Knight, ``but it's very, very beautiful. Everybody that hears me read it - either it brings the tears into their eyes, or else -''

``Or else what?'' said Alice, for the Knight had made a sudden pause.

``Or else it doesn't, you know. The name of the function is called 'Haddocks' Eyes'.''

``Oh, that's the name of the function, is it?'' Alice said, trying to feel interested.

``No, you don't understand,'' the Knight said, looking a little vexed. ``That is what the name is called. The name really is 'The Aged Aged Man'.''

``Then I ought to have said 'That's what the function is called?' '' Alice corrected herself.

``No, you oughtn't: that's quite another thing! The function is called `tri_area': but that's only what it's called, you know!''

``Well, what is the function, then?'' said Alice, who was by this time completely bewildered.

``I was coming to that,'' the Knight said. ``The function really is `A-sitting On A Gate': and the algorithm's my own invention.''

(WIth apologies to Lewis Carroll)

Answer 7

[Baalzamon]

This is not an answer as such but something I think will be a useful function.

Many times I have asked various questions - usually simple ones at that. Now I find that I learn best when reading, being shown and doing. This is to say explain, show with some code as an example and then I whizz off to try something on my machine.

I am all for people giving hints (though some often sound like vague and cryptic jargon to the unknowing - such as look at doc (functionX) ).

I am also totally in favour of people who want to give the code solution at any level. I learnt matlab by seeing code in other things and then using them for my stuff. Eventually I learnt a bit more and thought can I do this or this with that. Coding is not a race to be excellent at optimized/robust code and know your functions inside out but rather at its base level being able to make something that will assist your problem.

The function I would like to see is an option to hide the code! Much in the same way film sites hide the spoilers :(

This would have to follow hand in hand with people using the insert code thing instead of doing what I do and just type the code into the reply box o_O ( which I still haven't used or really know how to - I just skim over that section)

Answer 8

[Ifeanyi Dike]

Why am i having this error in my code? "Argument to the dynamic structure reference must evaluate to a valid field name "

Pls I need help with this question. I'm using 2018 version of matlab

[Walter Roberson]

S.x2 = 1;
S.x3 = 2

S = struct with fields:
    x2: 1
    x3: 2

We build a struct

F1 = 'x3';

S.(F1)

ans = 2

we can put a field name into a string, and we can use that string at execution time to read out the content of the field

S.(F1) = 5

S = struct with fields:
    x2: 1
    x3: 5

and we can use a string at execution time to name a field to write into

F2 = '3x';
S.(F2) = 6

Invalid field name: '3x'.

but that fails. We showed above that the syntax works fine, that you can generally do that. But notice the string we used before like 'x3' is a valid MATLAB variable name, but this newer one '3x' is not a valid MATLAB variable name. When you do this kind of reference, the strings need to be valid MATLAB variable names.

[Image Analyst]

@Ifeanyi Dike, when you posted your question in some other thread, and someone referred you here, that did not mean that you were supposed to simply post your question here instead. It meant that you were supposed to read this question and all its answers and realize that what you were supposed to do was to either fix your original post (which likely just posted the question with no attempt at solving it yourself), or to post it in your own question.

You and others should not post your actual homework problems here.