Group repeated values in an array and mention the repeated value with position

I need to group the repeated value in an array. After grouping the results should be

group = repeated value

position

Example:

a=[ 6 6 5 6 5 6 6]

Expected result:

group 1 = 5

3 5

group 2 = 6

1 2 4 6 7

Thank you in advance

[Rik]

What have you tried so far? I would try something with unique and ismember, or with histcounts.

[ASHA PON]

This is the code i have tried and results obtained are below

Code:

mxvalue=[6 6 5 6 5 6 6]

[out,i]=sort(maxvalue);

out1=diff(find([1,diff(out)]));

out2=[out1,numel(maxvalue)-sum(out1(:))];

out3=mat2cell(i,1,out2);

celldisp(out3);

Result:

out3{1} =

3 5

out3{2} =

1 2 4 6 7

In this result i'm able to get the positions of repeated value, but the repeated value is not displayed

Answer 1

[KSSV]

a=[ 6     6     5     6     5     6     6] ;
[c,ia,ib] = unique(a) ; 
for i = 1:length(c)
    fprintf('Group %d = %d\n',i,c(i))
    idx = find(ib==i)' ;
    disp(idx)
end

Group 1 = 5

     3     5

Group 2 = 6

     1     2     4     6     7

[ASHA PON]

Thank you for the support. This is what exactly i needed. The code works fine. Thank you once again