MATLAB: Ismember() returning without unique indexing

indexismemberunique

I want to get a result from ismember function such that

a =[{'aa'};{'bb'};{'cc'};{'dd'};{'ee'}];

b = [{'bb'};{'bb'};{'dd'};{'dd'};{'dd'};{'dd'}];

idx = find(ismember(a,b) == 1);

then idx = [2 4];

however, I want to get the results like idx = [2 2 4 4 4 4];

so, the frequency of cell array in b is conserved.

Would please somebody help me?

Thanks.

justin

Best Answer

[tf,loc] = ismember(b,a);
 loc.' =
   2     2     4     4     4     4

Related Solutions

MATLAB: Find indices of one array in another array.

[~,idx]=setdiff(A,B,'rows');
idx_rows=setdiff(1:size(A,1),idx)

MATLAB: Difference Between ismember() and contains()

They are not the same at all, they do quite different things!

ismember checks which complete elements of A are in B. The input arrays can be numeric, char, string, datetime, categorical, table, etc.
contains checks if the pattern occurs anywhere within any the elements of str. The input arrays are string array.

Have a look at the contains example:

>> str = ["Mary Ann Jones","Paul Jay Burns","John Paul Smith"];
>> pattern = "Paul";
>> TF = contains(str,pattern)
TF = 1x3 logical array
   0   1   1

Note that the pattern is not same as any complete element of str (it is only part of some of them). If you try the same with ismember it only matches the complete element:

>> TF = ismember(pattern,str)
TF = 1x3 logical array
   0   0   0
>> TF = ismember("John Paul Smith",str)
TF = 1x3 logical array
   1   0   0

Best Answer

Related Solutions

MATLAB: Find indices of one array in another array.

MATLAB: Difference Between ismember() and contains()

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