14.2 Project - Stellar Motion (Script). Can someone please help me with task 3 of the onramp?

I dont understand what to do can someone please explain and help me?

[Maryam AlKhoury]

I also need help with that!!!!! I've been trying to figure it out for hours!!

[Chinmay Padhye]

Its quite simple. You have to change the index from start 6 to 2.

[nicolas geo]

You need to perform the procedure again from previous test:

s = spectra(:,2);
%you choose the second star from spectra
[sHa,idx] = min(s);
%take the minimum value and perform the same code for the redshift
lambdaHa = lambda(idx);
z = lambdaHa/656.28 - 1;
speed = z*299792.458

[nicolas geo]

You need to perform the procedure again from previous test:

s = spectra(:,2);
%you choose the second star from spectra
[sHa,idx] = min(s);
%take the minimum value and perform the same code for the redshift
lambdaHa = lambda(idx);
z = lambdaHa/656.28 - 1;
speed = z*299792.458

[henry fuentes]

gracias por la ayuda

[nilesh nagrale]

you just need to change column number from 6 to 2

[HARPREET KAUR]

please help me for task 3. It is showing an error

for c = 1:7
    s = spectra(:,c);
    loglog(lambda, s , "--")
    if speed(c) <= 0
        
    end
    hold on
end

[Surya Karthik Nadupalle]

Hey anyone help me with last 4 questions 14.2 section of Matlab onramp. I'm stuck

[SATHISH KUMAR G R]

Even i am facing the same issue... its exactly same as solution but error occurs... i got struck

[selvi srinivasan ramu]

for v = 1:7

s = spectra(:,v);

if speed(v)<=0

loglog (lambda, s, '- -')

end

hold on

end

[Alok]

Project-compare steller spectra task 3 not showing how to find it

[Cris LaPierre]

You can see it in this screenshot below. If it's not loading in the course, you can try the suggestions given here. MathWorks recommends the Chrome browser.

You may also have connected to a bad server. You could try signing out, waiting 15 minutes, then signing back in.

Answer 1

[Cris LaPierre]

In case you have not noticed, you can view the solution for every task. Click the "See Solution" link.

[Norma Ulloa]

no really i've being clicking the soluction tab and it is not showing up anything

[Cris LaPierre]

Some additional options to try

• Restart your web browser
• Make sure your browser is supported and up-to-date
• Try a different browser
• Clear you cache and cookies
• Turn off any ad blocking software

[DGM]

If you're on a slow connection, you can expect a lot of the parts of the interface to simply be broken or missing completely. If the page elements are missing or unresponsive or if they give you connection errors or an infinite spinner, that's a possible cause to consider.

Answer 2

[Ghulam Nabi]

Project - Stellar Motion II Tasks 2–4 answer

[DGM]

As others have pointed out, the solutions are already available to you.

If there's some other thing you're asking about, you'll have to actually say what you want.

[Florence Ariadne]

Im having trouble on task 3, where it tells me to set the xlabel to "wavelength". I did it exactly how the solution does and it still tells me i didnt set the xlabel

[Cris LaPierre]

Have you spelled 'Wavelength' correctly? Capitalization matters, so be sure you are capitalizing the 'W'./

[James]

It is spelled the exact same way as the solution, however still won't put the label on the graph for this task

[Cris LaPierre]

Share your code or a screenshot of your solution and any feedback you receive.

[Brian]

As you can see here, my answer is exactly the same as the solution. However, it is still showing as incorrect.

[Cris LaPierre]

I'm intrigued by the red error indicator. Can you share what the error message is? Please copy/paste all the red text.

Even if I get the task wrong, I do not get that icon.

[DGM]

One possibility:

If you had accidentally done something like

xlabel = 'Wavelength';

in a prior attempt, that would cause an error after you corrected it, since xlabel is still being treated as a variable.

If that were the case, make sure to clear the unintended variables.

clear xlabel ylabel

There are probably other possible explanations.