How can I concatenate or merge two structures?

I would like to merge two structures into a new structure containing all the fields of the two original structures. How can I do this in MATLAB?

Answer 1

[MathWorks Support Team]

There is no direct ability in MATLAB that can be used to concatenate structures.

The attached file "mergeStructs.m" shows a number of methods that can be used to merge structures in MATLAB.

There are also online submissions on the MATLAB Central User Community that you can use. One such submission is:

https://www.mathworks.com/matlabcentral/fileexchange/7842-catstruct

Note that MathWorks does not guarantee or warrant the use or content of these submissions. Any questions, issues, or complaints should be directed to the contributing author.

[Royi Avital]

Is there a way which is MATLAB Codeer friendly?

Answer 2

[Ba Mo]

This works IF AND ONLY IF there are no common fields (duplicate fields) in the 2 structures.

mergestructs = @(x,y) cell2struct([struct2cell(x);struct2cell(y)],[fieldnames(x);fieldnames(y)]);

I don't see why nobody pointed this out. it's intuitive!

[Adam Danz]

Nice one, Ba Mo.

(Answer edited to format the line of code)

[KAE]

How do I execute this if I have two structures named Struct1 and Struct2?

Answer 3

[James]

You can do this manually:

 f = fieldnames(structA);
 for i = 1:length(f)
    structB.(f{i}) = structA.(f{i})
 end

Answer 4

[John Beaumont]

Convert structures to tables, then merge tables, then convert resulting table back to a structure.

% Create 1st structure
aa_s.val1 = 1;
aa_s.val2 = 2;

% Create 2nd structure
bb_s.val3 = 3;
bb_s.val4 = 4;

% Convert structures to tables
aa_t = struct2table( aa_s );
bb_t = struct2table( bb_s );

% Concatonate tables
merge_t = [ aa_t ,bb_t ];

% Convert table to structure
merge_s = table2struct( merge_t )