create an array of single struct

structElement = struct('a1','', 'a2', '', 'a3', '', 'a4', '');
s1 = repmat(structElement, [1,1]);

The above code gives a 1x1 struct

s2 = repmat(structElement, [2,1]);

The above code results in a 2x1 struct

If I do s2(1) it returns a struct
If I do s1(1) it returns a1.

How can I create s1, such that s1(1) will give me back a struct. Basically I want to create an array of single struct.

[Adam]

Both those syntaxes return the full struct. They do in Matlab R2015b that I am using.

s1 = structElement;

would do though. The repmat instruction is redundant.

[Guillaume]

I'm fairly certain they've done so in every version of matlab (barring any bug).

It would never make any sense for an index to return a field of a structure. Particularly since everything in matlab, including scalar structures, is always an array.

Answer 1

[Guillaume]

"If I do s1(1) it returns a1." No, it also returns a structure.

Both s1 and structElement are arrays of a single struct:

>>s1(1)
ans = 

     a1: ''
     a2: ''
     a3: ''
     a4: ''

>>size(s1)
ans = 
     1      1

>>size(structElement)
ans = 
     1      1

Everything in matlab is an array. Scalars (numbers, structs, objects, etc.) are stored as array of size 1x1

[Aditya Jain]

My bad. You are right. Is there a way I can create a cell array of structs instead of normal matrix?

[Walter Roberson]

s2 = repmat({structElement}, [2,1]);

[Guillaume]

You can create cell arrays of structures the same way you create cell arrays of numbers, by plain assignment, using arrayfun / cellfun, using num2cell, etc.

s = struct('a', {1 2 3 4 5}, 'b', ''); %creates a 1x5 array of struct
c = num2cell(s); %convert matrix to cell array

Another way:

s = struct('a', '', 'b', ''); 
c = cell(2, 5);
c(:) = {s};

However, if all the structures have the same fields, I don't see the point of storing them in a cell array.