Problem with renaming dublicated variablenames

Hi experts,

I want to rename a bunch of variables (ppn) by extending them with '_01' and I want to extend duplicate variablenames with '_02'. The problem is that I get variables named 'BG1028_02_01'. I hope someone can help me!

     ppn = {'BG1026';'BG1027';'BG1028';'BG1028';'BG1029';'BG1030'}

   for i = 1:length(ppn)-1
    j = i + 1;
    d = strcmp(ppn{i},ppn{j});
    if d == 0;
        ppn{i} = strcat(ppn{i},['_01']); 
    else d = 1;  
        ppn{i} = strcat(ppn{i},['_01']); 
        ppn{j} = strcat(ppn{j},['_02']);
    continue;
    end
end

This is what I get:

ppn = 

      'BG1026_01'
      'BG1027_01'
      'BG1028_01'
      'BG1028_02_01'
      'BG1029_01'
      'BG1030'

[Kirby Fears]

Do you want a general solution in case you have more than 2 duplicates? In the future, could you end up having 99 duplicates in a row?

Answer 1

[Kirby Fears]

As long as you expect no more than 99 duplicates, this should solve your problem. You can remove the sort() call if your names will arrive sorted in the first place.

% Example list of names
ppn = {'BG1026';'BG1026';'BG1027';'BG1028';'BG1028';'BG1028';'BG1028';'BG1029';'BG1030'};

% Ensure that list is alphabetically sorted
ppn = sort(ppn);

% Append ones to everything
ppn = cellfun(@(s)[s '_01'],ppn,'UniformOutput',false);

% Check if any string is equal to previous string
idx = find(strcmp(ppn(1:end-1),ppn(2:end)))+1;

% Loop to rename variables
counter=2;
while ~isempty(idx) && counter<100,
    % Turn duplicate counter into 2-digit string
    counterstr=num2str(counter);
    if length(counterstr)==1,
        counterstr = ['0',counterstr];
    end,
    % Replace all duplicates with new counterstr
    for iter=1:numel(idx),
        ppn{idx(iter)}(end-1:end)=counterstr;
    end,
    % Update duplicate idx for next round of loop
    idx = idx(strcmp(ppn(idx),ppn(idx-1)));
    counter = counter+1;
end,

[Marty Dutch]

Thanks a lot! This code is much better than what I wrote. I have 528 dubplicates and it handles all of them.

[Kirby Fears]

The code above assumes that any individual name will not appear more than 99 times. E.g. BG1028 should not appear more than 99 times.

However, any number of variables (528 in your case) can each have up to 99 duplicates.

[Marty Dutch]

Okay, I understand it now. The number of duplicates is no more than 5. Thanks for your time and help!

Answer 2

[dpb]

ppn=strcat(ppn,'_01');  % add the '_01' at the git-go...
[~,~,ib]=unique(ppn);   % get a list of unique name positions
[n,ix]=histc(ib,1:5);   % count and locate if any duplicates
for i=1:length(n)       % and process the list and fixup if needed...
  if n(i)>1
    for j=2:n(i)
      k=ix(i)+j-1;
      ppn(k)=strrep(ppn(k),'_01',num2str(j,'_%02d'));
    end
  end
end

BUT, DO NOT DO THIS!!! See the FAQ for why not and ways to avoid same...

How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop?