How do I plot from excel different columns file?

Hello everyone. i am completely new to Matlab and I have a problem with an exercise in my practice book. I have a file in excel looking like this:

a  b  c  d  e  f  g  h
1  6  7  4  3  3  4  7
2  6  6  6  6  6  6  6
3  4  3  7  9  3  6  7
4  9  5  3  1  2  2  6
5  7  9  4  7  3  3  2
6  4  6  7  8  9  5  6

I had no problem importing it. Now i want to visualize the column "c","f" and "h" it in a graph with column "a" being the x-axis. I tried stuff like this

[numbers, txt, raw] = xlsread("filename");
colc = numbers(:, 3);
colf = numbers(:, 6);
colh = numbers(:, 8);

But now i am getting nowhere. How do i continue? I´m trying for around 2 hours at this point😅

Answer 1

[John D'Errico]

You were ALMOST there. Literally, almost. You need the x axis variable. Here is your array:

numbers = [1  6  7  4  3  3  4  7;2  6  6  6  6  6  6  6;...
    3  4  3  7  9  3  6  7;4  9  5  3  1  2  2  6;...
    5  7  9  4  7  3  3  2;6  4  6  7  8  9  5  6];

Now extract the columns you care about.

cola = numbers(:,1);

colc = numbers(:, 3);
colf = numbers(:, 6);
colh = numbers(:, 8);

So you pretty much had that. I just added the cola. Now call plot.

plot(cola,[colc,colf,colh],'-o')
legend('C','f','h')

So three curves, although they overlap at the first few points, so you might not see them as different.

[Karl-JR]

Oh okay, thank you very much. Just a little question. Is it possible to define the x- and y- Axis for example like x axis is Quality and y- axis is Quantity?

[John D'Errico]

I'm not absolutely positive what you mean by define, since a plot is just a picture. I think you mean to provide axis labels. You can also have a title label on top of the plot.

plot(1:5,rand(1,5),'o-')
xlabel 'Quality'
ylabel 'Quantity'
title 'Furlongs per fortnight' % I'm not very creative about a good title. sorry.

And in three dimensions, there is zlabel, which does not apply here.

[Karl-JR]

Wow, you helped me a lot. Thank you🙏😁