MATLAB: I have a character vector with repeated elements and want to extract each element once and at the sequence of appearance.

character vector

Hi all,

I have a character vector with repeated elements and want to extract each element once, at the sequence of appearance in the original file. I am attaching an example file. In fact, I need to get:

Group Frontal_L Ins_Cing_L etc..

I guess I will have to use regexp but not very experienced with this functionality. Any ideas very welcome.

Best Answer

[unames,ia,iu]=unique(strtrim(cellstr(Getcurvenames)),'stable');
unames will be the names that are unique in the overall list,
unames=Getcurvenames(ia);  % ia is location vector in original list Getcurvenames
Getcurvenames=unames(iu);  % rebuild the original from the indices in unique list

unames will be cellstr list of names, much more conveniently handled than are fixed-length char arrays.

ADDENDUM

I forgot about the request for initial order in the output; use the 'stable' option as shown above. To not return the group string, make a slight modification to eliminate it first --

cnames=strtrim(cellstr(Getcurvenames));     % convert to trimmed cellstr
cnames=cnames(~contains(cnames,'Group'));   % keep only those ~='Group'
[unames,ia,iu]=unique(cnames)),'stable');   % and the unique list of those

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Try this:

A = randi(1000, 60, 5);                                 % Create Matrix
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keep = tally > 1;                                       % Keep Indices Of Occurrences > 1
out1 = [Au(keep), tally(keep)];                         % Display Numbers & Occurrences
Ai = ismember(A,out1(:,1));                             % Return Logical Index Of Occurrences > 1
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The ‘Anew’ matrix has 0 values for the elements that are not repeated, those that are repeated appear in their expected locations.

If you only want the values of the numbers that aare repeated, and the number of repeats, those are contained in the ‘out1’ matrix.

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Such cases are handled using persistent variables.

function [ia_avr] = fcn(ia)
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Best Answer

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