Find unique values in array

Hi,

I have a 7x700 array, theta, with repeated values in each row of the array. I would like to create a new array which is all the unique values in each row of theta. Simplified example of what I mean:

theta=[1 2 3 1 2 3 1 2 3; 4 5 6 4 5 6 4 5 6; 5 4 2 5 4 2 5 4 2]

desired output=[1 2 3; 4 5 6; 5 4 2]

I'm guessing I'd need a for loop to go through all 7 rows and the 'unique' command but I didn't get the right result.

Thank you

Answer 1

[DGM]

Since there's generally no guarantee that the rows have the same number of unique elements, then I wouldn't assume that would work. Unless you can guarantee that for your specific case, then use a cell array to store the output. Since you didn't say why the result wasn't right, I'm just going to guess.

theta = [1 2 3 1 2 3 1 2 3; 4 5 6 4 5 6 4 5 6; 5 4 2 5 4 2 5 4 2]

theta = 3×9

1 2 3 1 2 3 1 2 3 4 5 6 4 5 6 4 5 6 5 4 2 5 4 2 5 4 2

nrows = size(theta,1);
T = cell(nrows,1);
for r = 1:nrows
    T{r} = unique(theta(r,:),'stable');
end
celldisp(T)

 
T{1} =
 
     1     2     3

 
 
T{2} =
 
     4     5     6

 
 
T{3} =
 
     5     4     2

 

I suppose it's possible to convert the cell array to a numeric array if it turns out to be rectangular.

T = cell2mat(T)

T = 3×3

1 2 3 4 5 6 5 4 2