bar chart for an array

I'm trying to create a bar chart for a matrix, its a 1x30 but I only want the 0, 10th, 20th and 30th values.

I've tried many formats such as in the image but I cannot manage to get it working.

Any suggestions out there?

Answer 1

[Ameer Hamza]

I MATLAB, use the following syntax to index into an array.

bar([1 10 20 30], mean_1_1_walk([1 10 20 30]))

Also in MATLAB indexing start from 1, unlike some other programming languages (such as c/c++, java, python) where indexing starts from 0.

[dpb]

"... unlike most other programming languages."

"... unlike one other particular programming language."

[Jordanf1519]

That sorted it, thank you.

[dpb]

Also note you can write expressions like

mean_1_1_walk([1:10:end])

besides a list of specific indices.

[Jordanf1519]

Would you also happen to know how to have the bars side by side instead of stacked when plotting more than one matrix?

[Ameer Hamza]

@dpb OP is indexing them like [1 10 20 30] for some reason. Therefore I wrote it like that.

@Jordanf1519 refer to this example. For your case the command becomes

bar([1 10 20 30], [mean_1_1_walk([1 10 20 30])' mean_1_2_walk([1 10 20 30])']);

[dpb]

Indeed he did, but he also started counting from 0 instead of 1. It's quite possible he didn't know could write an expression; was simply giving alternate syntax as tutorial additional information.

[Jordanf1519]

Would anyone know how to change the colours of these bars too?

bar([1 10 20 30], [mean_1_1_walk([1 10 20 30])' mean_1_2_walk([1 10 20 30])']);

[Ameer Hamza]

You can find several examples on documentation page which will help you to do this: https://www.mathworks.com/help/matlab/ref/bar.html#d119e66370.