Problem with answer 15.2 Creating and Calling Functions: (4/6) Create and Call a Function, task 1 MATLAB Fundamentals

The problem asks us to modify the function call using two inputs. I put the answer as follows:

top5 = getLargestN(x,5)

i get a message 'error using exercise>getLargestN too many input arguments'.

The answer i solution is identical to one I gave. How do I move forward here?

Answer 1

[Geoff Hayes]

Gareth - did you update the function signature as well so that it accepts two inputs? Presumably you have defined the function (with body) like

function [res] = getLargestN(x)

and you would need to change this to

function [res] = getLargestN(x,y)
% do something in code with y

so that the signature matches how you are calling it (when you pass in the x and 5).

[Gareth George]

Hi Geoff, thanks for reaching out. I removed the 'function' in the version I sent becuase that wasn't working either. The task is just to modify the function call in this instance. So I'm running exactly this:

function Y= getLargestN(x,5)
    top5=Y
end

the task is here:

1. Modify the script so that the function takes two inputs. The second input should represent the number of the largest elements to return. For example,t = getLargestN(v,5)should output a vector containing the five largest elements of v.
2. Modify the function call in the script and store the five largest elements in a vector named top5.

my result here: Test Results:

Incorrect!

Check that x is not modified. X

Does the function evaluate correctly? X

no idea how i'm modifying x here

[Geoff Hayes]

Gareth - I would first try to get the function returning the correct response (I don't understand either what "check that x is not modified" means). So right now your function is

function Y= getLargestN(x,5)
    top5=Y
end

There are a couple of problems. The signature defines the output parameter and the input parameters. These parameters are variables and since 5 is not a variable (but a value) you cannot define it as a parameter. (You can pass 5 into this function when you call it.) So change this to something like

function Y = getLargestN(x, numElements)

Try to name the variables as to their purpose. Next, the output parameter is Y but is not set anywhere in your code. In fact, you are trying to use it before it has been defined. (I think the top5 variable is meant to be the output from this function when you call it...and not a variable within the function because you don't know how many elements you will be asked to extract.

function Y = getLargestN(x, numElements)
    Y = ...;
end

Now you just have to sort the data.

[Gareth George]

Thanks Geoff! I got there in the end. Really helpful. I've been used to doing these tasks one at a time, so didn't anticipate having to edit code in a window further down first :)

Answer 2

[Sanket]

y0 = 0.4;

yline(y0)

tzerox = findcrossing(t,x-y0)

tzeroy = findcrossing(t,y-y0)

Answer 3

[Bhavesh Pawar]

y0 = 0.4;
yline(y0)

tzerox = findcrossing(t,x,y0)
tzeroy = findcrossing(t,y,y0)

[Oguz Tan]

The real solution is different than the solution which the course gives.

y0 = 0.4;
yline(y0)

tzerox = findcrossing(t,x-y0)
tzeroy = findcrossing(t,y-y0)

[Jorge Luis Argel Pacheco]

gracias

[Jorge Luis Argel Pacheco]

esa tampoco es

[Enes Çelik]

Thank you so much Oguz!

[Lester]

Thank you, the code helped me.!

Answer 4

[Joed Blair Jacalan]

1. Modify the definition of the findcrossing function so that it takes a third input z.
2. Add a new line to the beginning of the function:y = y - z;
3. In the Task 1 section of the script, change the value of y0 to 0.4.
4. Modify the two calls to findcrossing to add y0 as an input.

You can use the graph to check that the returned values of t are correct (x(t) = 0.4 and y(t) = 0.4)