Sort struct fields by their length

Hi everyone,

i have a struct of N fields in random order, each one is composed by an array Nx1. What i need to do is to sort the order of fields by their lengths, so that the first field would be the longest one and the last filed would be the shortest one.

Can anyone help me?

Thanks!

Answer 1

[KSSV]

% MAke structure for demo 
S = struct ;
for i = 1:10
    S(i).val = rand(randsample(100,1),1) ;
end

%% Gt lengths of each structure fields 
L = zeros(length(S),1) ;
for i = 1:length(S)
    L(i) = length(S(i).val) ;
end
% sort into order 
[L,idx] = sort(L) ;
S = S(idx) ;   % arrange 

[Luna]

This is 1xN struct array with one field (val). S(idx) might not work if he has a 1x1 struct with N fields.

Answer 2

[Luna]

Hi,

Try this:

% Create myStruct with Alphabet Fields and add random 1XN array to the
% fields
fieldList = cellstr(('a':'z')')';
for i = 1:numel(fieldList)
myStruct.(fieldList{i}) = rand(1,randi(30));
end

%% Sorting starts here
myCell = struct2cell(myStruct); % convert to cell array 
lenghtofFields = cellfun(@length,myCell,'UniformOutput',false); % get the lengths
[vals,orders]  = sort(cell2mat(lenghtofFields),'descend'); % get the orders from sorted lenght
structFieldNames = fieldnames(myStruct); %get your struct's fieldnames (I could use fieldList but you can avoid above creation section)
NewStructwithOrderedFields = orderfields(myStruct,structFieldNames(orders)); % order fields according to orders array

Answer 3

[Alex Mcaulley]

Another option:

a.one = rand(1,10);
a.two = rand(1,15);
a.three = rand(1,8);
a.four = rand(1,12);

[~,idx] = sort(structfun(@numel,a),'descend')
a = orderfields(a, idx);