Remove elements within a range from an array

Hi,

I have an array called A, which could have the example values shown below:

A = [1 1.2 3 3.1;

1 1.3 3 3.2;

2 2.1 4 4.1;]

Now, I want to be able to remove the columns that are near-duplicates (in this case within a 0.5 range of another column) and I am having trouble doing so.

For clarity:

I want the final array to just be:

A = [1 3;

1 3;

2 4]

Any help would be greatly appreciated. ALSO: it does not matter which duplicate gets removed, as long as in the end there is only 1 column that represents the numbers within that range (so the 1 1 2 column could be removed instead of the 1.2 1.3 2.1 column). NOTE: the real array I would be operating on is variable in size so I need a solution that will work for any size array.

Thanks for the help I really appreciate it!

Answer 1

[DGM]

I'm going to assume that near-duplicate columns happen neatly and that only complete near-duplicate columns count

A = [1 1.2 3 3.1;
     1 1.3 3 3.2;
     2 2.1 4 4.1]

% pick some tolerance
tol=0.5;
goodcols=find([1 any(abs(diff(A,1,2))>=tol,1)]);

Agood=A(:,goodcols)

gives us:

Agood =
     1     3
     1     3
     2     4   

Of course, this doesn't account for a split-duplicate like this:

A = [1 1.2 3 3.1;
     1 1.3 3 3.2;
     2 3.9 4 4.1]

and the split-dpulicate column wouldn't get removed

Agood =
            1          1.2            3
            1          1.3            3
            2          3.9            4

I don't know if that's appropriate for your task or not.