How to find indices of similar elements in a vector?

I have a vector x=[1 1 2 2 3]. I want to find out the indices of the elements that are similar. The desired output should be something like this. indices = 1,2 & 3,4

[Jan]

See duplicate post: https://www.mathworks.com/matlabcentral/answers/351128-how-to-find-indices-of-similar-values-in-a-vector

Answer 1

[Geoff Hayes]

Syed - try the following

 x = [1 1 2 2 3];
 groupedData = arrayfun(@(y)find(x == y), unique(x), 'UniformOutput',false);

In the above, we use arrayfun to loop over each unique element of x and apply the function

 @(y)find(x == y)

which returns the indices of those elements of x that are identical to that unique element (the input y).