To remove the repeated number

i have a matrix [1 2 2 2 3 4 5] and i want to get the result has [1 2 3 4] by replacing the repeated 2 by the single number.

[Jos (10584)]

and get rid of the 5 as well?

Answer 1

[Brian B]

Use

 unique([1 2 2 2 3 4 5])

Note that this will also sort the elements.

-B

Answer 2

[Andrei Bobrov]

% without sorting array

m = randi(5,1,10);

[~,ii] = sort(m);          % for Jan's solution
jj = [true,diff(m(ii))~=0];
out1 = m(sort(ii(jj)));

out2 = unique(m,'stable'); % in R2012a and later

[u,b] = unique(m,'first'); % old releases
[~,ii] = sort(b);
out3 = u(ii);

[Jan]

Very old releases do not know the 'first' flag in the unique() command.

Answer 3

[Jan]

No sorting, considering only neighboring elements such that e.g. [1,2,1] is not altered:

m = [1 2 2 2 3 4 5];
u = m([true, diff(m) ~= 0]);

You see, there are many different solutions, because your problem is not defined exactly: Sorting, not neighboring repetitions, ...