Is it possible to concatenate structures with the same fields in to one super structure?

I have structures c and c1, each contain 55 fields with the same names.

The field dimensions differ slightly in the x domain (ie):

c.E: [68×120 single]
c.N_z_cross: [68×120 single]
c.N_z_long: [68×120 single]

and

c1.E: [84×120 single]
c1.N_z_cross: [84×120 single]
c1.N_z_long: [84×120 single]

ideally I would like to create a structure that contains both continually (ie)

full_data.E: [152×120 single]
full_data.N_z_cross: [152×120 single]
full_data.N_z_long: [152×120 single]

Is there anyway to do this without manually concatenating each variable?

Thanks in advance.

[Stephen23]

"Is it possible to concatenate structures": yes, it is certainly possible to concatenate structures together:

[struct1,struct2]

will concatenate two structures together. But what you describe in the body of your question is how to to concatenate structure fields together, not the structures themselves. Both of these things are possible, but require very different code.

Answer 1

[Jan]

Or with a loop:

function S = CatStructFields(S, T, dim)
fields = fieldnames(S);
for k = 1:numel(fields)
  aField     = fields{k}; % EDIT: changed to {}
  S.(aField) = cat(dim, S.(aField), T.(aField));
end

Then:

full_data = CatStructFields(c, c1, 1)

[Stephen23]

+1 simple and efficient. Can be generalized to any number of structures:

function S = CatStructFields(dim, varargin)
F = cellfun(@fieldnames,varargin,'uni',0);
assert(isequal(F{:}),'All structures must have the same field names.')
T = [varargin{:}];
S = struct();
F = F{1};
for k = 1:numel(F);
    S.(F{k}) = cat(dim,T.(F{k}));
end
end

[Murat Aydin]

I had the same question, but I'm getting an error from this code, which is based on what is above, written for two structures Chain1 and Chain2 that have the same fields in the same order.

fields = fieldnames(Chain1);
for k = 1:numel(fields)
  aField     = fields(k);
  fit.(aField) = cat(1, Chain1.(aField), Chain2.(aField));
end

Error: Argument to dynamic structure reference must evaluate to a valid field name.

Basically, it does not accept Chain1.(aField) - or using aField cell to refer to a structure field in general - as valid syntax.

[Stephen23]

@Murat Aydin: the error is easy to indentify: fieldnames returns a cell array of character vectors, but the dynamic fieldname syntax requires a character vector. So you just need to use the correct indexing to get the character vector out of the cell array:

aField = fields{k};

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

Answer 2

[Ba Mo]

my_struct_fields = fieldnames(my_struct1);

super_struct=arrayfun(@(i) [my_struct1.(my_struct_fields{i});my_struct2.(my_struct_fields {i})],[1:numel(my_struct_fields)]','un',0);

my_dirty_trick = [my_struct_fields,super_struct]';

final_struct = struct(my_dirty_trick{:});

Thank you for officially accepting my answer

Answer 3

[Rubens Rossi]

Thank you for the solution. I modified CatStructFields to handle my structures, which rows are 'channels'.

% Important: field position can be different between the two structures,
% but not the row position (e.g. channels), which do not have names.
S=varargin{1};
for idxV = 1:length(varargin)-1
    
    T=varargin{idxV+1};
    for k = 1:numel(F)
        for h = 1:length(S)
            S(h).(F{k}) = cat(dim,S(h).(F{k}),T(h).(F{k}));
        end
    end
end

Answer 4

[aooEo]

hello, i also faced the same problem, after seeing above answers i did not build a function and use the for cycle to solve the problem, maybe it is also a idea to encourage you.

fields = fieldnames(F1);

sum_F1 = repmat(empty, numel(F1)+numel(F1_fore), 1);

for k = 1:numel(fields)

for i = 1 : numel(F1)

sum_F1(i).(fields{k}) = F1(i).(fields{k});

end

end

for k = 1:numel(fields)

for i = numel(F1)+1 : numel(F1) + numel(F1_fore)

sum_F1(i).(fields{k}) = F1_fore(i-numel(F1)).(fields{k});

end

end