Accessing Matlab structure array without field names

Question

I have a structure with two unnamed fields that I need to access individually as vectors. The matlab help page only has examples with field names.

How do I retrieve an unnamed field?

Edit

For example, my data looks like this:

0.5000  0.1338
0.4999  0.1445
0.4998  0.0716

and not like:

x       y
0.5000  0.1338
0.4999  0.1445
0.4998  0.0716

It's not clear what you mean by an unnamed field in a structure. All fields by definition require a name. Can you include sample data in your question? — b3.
– b3., Commented Jun 22, 2017 at 22:51
Are you certain you're dealing with a structure, and not a table or other data type? You can check the data type with class(s), where s is the variable holding your data. — gnovice
– gnovice, Commented Jun 23, 2017 at 0:20
My data is apparently a table inside a structure. I used the term field interchangeably with column when I meant the latter. I see where that was inappropriate particularly given the context of a matlab structure. Thanks for your assistance. — user8176353
– user8176353, Commented Jun 23, 2017 at 0:43

gnovice · Accepted Answer · 2017-06-22 22:59:42Z

4

If you don't know the field names a priori, you can use fieldnames to get them, then access them using the returned values:

names = fieldnames(s);
vec1 = s.(names{1});
vec2 = s.(names{2});

Alternatively, you can ignore them altogether and just place the structure field contents in a cell array using struct2cell:

vecs = struct2cell(s);
vec1 = vecs{1};
vec2 = vecs{2};

answered Jun 22, 2017 at 22:52

gnovice

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