Accessing Elements in Arrays

I have an array like this:

s.x

ans = 4000

280

ans = 4272.5

282

ans = 4553.85

284.29

etc......

I would like to access the first element in each case to plot their values (4000 4272.5 4553.85).

s(1,1).x([1]) yields 4000

s(1,2).x([1]) yields 4272.5

s(1, 1:2).x([1]) gives error: a cs-list cannot be further indexed.

What is the proper syntax needed to yield an array containing the values 4000 4272.5 and 4553.85 please?

Answer 1

[Ameer Hamza]

You can use arrayfun()

v = arrayfun(@(s_) s_.x(1), s)

Indexing of struct arrays and cell arrays can be a bit confusing in MATLAB. Check the following links

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-structure-array.html

https://www.mathworks.com/help/matlab/matlab_prog/multilevel-indexing-to-access-parts-of-cells.html

Following is another solution

v = [s.x];
v = v(1,:);

[Chris Stillo]

Thanks,

arrayfun works for me, although I think I'll just use it for now and try to understand it later!

[Ameer Hamza]

I am glad to be of help! :)

In short, arrayfun is just a for-loop. Following two codes are same

v = arrayfun(@(s_) s_.x(1), s)

or

v = zeros(size(s));
for i = 1:numel(v)
    v(i) = s(i).x(1);
end

[Chris Stillo]

That's great. Thanks again.

[Ameer Hamza]

I am glad to be of help!