How to add (combine) together two structures with the same fields?

Dear All,

I have two structures A and B with the same fields. How can I combine them together to form a new structure?

For example, A = struct('field1', array1, 'field2', array2); B = struct('field1', array3, 'field2', array4). A and B have the same fields 'field1' and 'field2'. I want to combine A and B together to obtain structure C = struct('field1', [array1; array3], 'field2', [array2; array4]). array1 and array3 have the same number of columns, and array2 and array4 have the same number of columns.

Thanks.

Benson

[Geoff Hayes]

Benson - what should the new structure look like? If A and B have the same fields, then does that mean that the combined A and B have array fields? Please illustrate with a small example.

[Benson Gou]

Hi, Geoff,

Please see my question again.

Thanks.

Benson

Answer 1

[KSSV]

clc; clear ;
s1.name = 'Tom' ;
s1.sex = 'm';
s1.age = 25 ;

s2.name = 'Harry' ;
s2.sex = 'f';
s2.age = 26 ;

% Structure array
s = [s1 ; s2] 
% Single structure
S = struct ;
aField     = fields(s1);
for i = 1:3
    
    S.(aField{i}) = {s1.(aField{i}) s2.(aField{i})} ;
end
S

[Benson Gou]

Hi, KSSV,

Thanks for your reply. Is it possible to avoid the For iterations? Because I already have the structures A and B. I believe that there is a way to directly combine them together without For iterations.

Thanks.

Benson

[KSSV]

How are your structures?

[Stephen23]

Note that the loop does not concatenate the field data as your qustion shows, but instead nests the field data within a 1x2 cell array.

[dleal]

Hi, I have a similar question..

given two structs with numerical values:

S1 = struct; S2 = struct;

S1.A = [1,2]; S1.B = [3, 4];

S2.A = [9,10]; S2.B = [11,12];

is there a way to combine them into S3 so that S3.A = [1,2,9,10] and S3.B = [3,4,11,12]?

I would just do it with a for loop, but I wonder if there is a way that might be less expensive:

S3.A = [];

S3.B = [];

fNames = fieldnames(S1);

for jj = 1:numel(fNames)

S3.(fNames(jj) = [S1.(fNames(jj)) , S2.(fNames(jj)) ];

end