MATLAB Fundamentals course problem

Hi, I have a problem in this course in this part: "5.11 Reshaping Arrays: (7/8) Overall Average Electricity Revenue" for task 1. I receive an error message even if my answer is correct. It doesn't find the variable named avgRev. Can anyone help me? Thanks, Nicholas

[Image Analyst]

Probably . . . if you give us your code!

But read this link first.

[Chaitanya Chitale]

This issue is now fixed.

Answer 1

[Chaitanya Chitale]

This is a bug in certain practice problems in the MATLAB Fundamentals and the Machine Learning with MATLAB courses caused by the use of the function boolean in the grading code. This function is only available in Simulink which is not available in the online course environment.

We are working on fixing the bug as soon as possible.

As a workaround, please add the following line of code at the top of the MATLAB script before submitting:

boolean = @logical;

[Nicholas Caputo]

It works. Thank you so much!

Answer 2

[Jan]

 Can anyone help me?

Yes. Or no. It depends on what kind of help you want.

The error message is clear already: It is tried to use the variable "avgRev", but it has not been created before. The message contains the line, where the code fails. Open it in the editor and find out, where you have to provide this variable or where to create it. Perhaps it is a typo only.

For a more specific help, we need the (relevant part of the) code, the complete error message and the code you use for calling this function (or do you use the "Run" icon in the editor?).

[Nicholas Caputo]

It doesn't give me an error message. The task doen't find variable even if I Run the code and I submit it. The task is: "Calculate the average electricity revenue over all time, and name the result avgRev." The code is:

load electricity

    %%TODO - TASK 1: Calculate the average electricity revenue over all time
    avgRev= mean (reshape(revenue,[],1))

[Jan]

From your question:

 I receive an error message even if my answer is correct

From your comment:

 It doesn't give me an error message.

This is a confusing combination. What does this sentence mean exactly:

 The task doen't find variable even if I Run the code and I submit it.

Which task? What does "finding a variable" mean? How do you know, that "it" does not "find a variable"? Perhaps because you get a message? If so, which one? How do you "run" which code and where do you submit what?

Sorry, I do not understand what you are trying to do and what is failing. Please provide an explanation which allows to reconsider, what you want, do and observe.

[Nicholas Caputo]

I am doing Matlab Fundamentals course. In particular, in chapter 5.11 the task 1 is to calculate the average electricity revenue over all time and name the result avgRev. I did it but the course doesn't find the variable and so I can't go to task 2. I attach a screenshot of my desktop.

[gs]

I'm experiencing the same problem

[Image Analyst]

Looks like a bug to me. I mean how could it even give you a check mark in the second line if the first line has a red x? I'd report it to the Mathworks.

One thing to try is to call plot() in line 7 and see if that lets Task 2 be enabled.

[gs]

Task 2 can't be enabled without passing Task 1. I think the bug is the use of "boolean" instead of "isboolean" in the assert command in the test suite. I attach a screenshot of the test suite details.

[Jan]

isboolean is not useful here, because exist replies a double with an integer number. Try to define boolean as in a dummy in the code:

boolean = @(x) x

Answer 3

[gs]

I've encountered a similar bug in part: "6.1 Project - Halfway Review of Fundamentals: (2/3) Women's 200m Backstroke". I attach the code of the test suite details:

t1__ = (boolean(exist('name')))
t2__ = (boolean(exist('country')))
t3__ = (boolean(exist('time')))
assert(t1__ && t2__ && t3__)

[Nicholas Caputo]

I have the same problem here too.

Answer 4

[Walter Roberson]

In another related Question, Mathworks said it is a bug that they will repair ASAP.

Unfortunately I cannot find that question now to make sure they know to look at all the various chapters.