unique_no_sort

Like unique.m but without sorting

Description

Returns the unique elements of a vector, matrix or cell array in the order that they first appear in the input. Does not operate on rows like the original unique.m.

• MATLAB release: MATLAB 7.1.0 (R14SP3)

[Thomas Cunningham]

Great idea!

I needed something like this, but for cell arrays of strings, which get alphabetized. Any chance that this is easy to do?

[Thomas Cunningham]

My apologies. Of all the silly things, I forgot to move the file into my working directory! I'd give it a 5 if I know anything about metyrics, but it worked for what I needed it for so four it is!

[Joshua Apgar]

Works as advertised, could be faster though.

[g s]

needs an option to operate on rows like the original matlab UNIQUE function

[Joshua Apgar]

Thanks for vectorizing the code. It is blazing fast now!

[no so good]

>> a=magic(1000);
>> tic;unique_no_sort(a);toc
Elapsed time is 0.919820 seconds.
>> tic;unique(a);toc
Elapsed time is 0.313802 seconds.

[student student]

Thank you Thank you Thank you
You are a good person.

[not 4 you to know]

just replace lines 97 to 110 with b=a;

>> a=magic(1000);
>> tic;unique_no_sort(a);toc
Elapsed time is 0.058435 seconds.
>> tic;unique(a);toc
Elapsed time is 0.285986 seconds.

[not 4 you to know]

in unique.m you have to replace those lines...just adding this to make sure. :)
sorry for taking two posts to tell this

[reza j]

How about something slightly simpler:
function [unsorteduniques ia ib] = uunique(vec)
    vec = vec(:)';
    [v a b] = unique(vec, 'first');
    if nargout > 2
        [ia v] = sort(a);
        [v ib] = ismember(b, v);
    else
       ia = sort(a);
    end
    unsorteduniques = vec(ia);
end

[Matthias]

thanks, saved me making my own script!

[dirt]

Found a bug - it sometimes doesn't return the N correctly (I haven't tested it further).

[dirt]

nevermind ... wishful thinking for something else.

[Timothy Kinyanjui]

Thanks. Very very useful.

[Vanich]

Thx so much