Insert new values in specific position after processing

I have a vector A of logical datatype size 5 x 1

A = [1 0 0 1 1 ];

Then I extracted the features where A = 1

ind1 = A(:,1) == 1;
A1 = Feat(ind1,:);

After processing I obtained a new vector

Anew  = [ 1 0 1]

Now I want to insert the Anew back to A in the same position to obtain the result as

[1 0 0 0 1]

When I insert the vector back the values are not coming correctly.

Please can someone help me to insert Anew to A in the same position.

The size of vector A can vary

Answer 1

[Askic V]

In such stuations, I would keep track of indices of elements in the original vector, use find function.

A = logical([1 0 0 1 1]);

ind = find(A == 1)

ind = 1×3

1 4 5

% processing

Anew = logical([1 0 1]);

A(ind) = Anew

A = 1×5 logical array
   1   0   0   0   1

If you really need to change and process the original vector, then instead of removing element in it, place Nan in its position as a placeholder.

[Elysi Cochin]

Sir could you please suggest an efficient way to do this

When the size of the A increases, the number of elements I extract with 1 is wrong.

Sir could you please suggest an efficient way first extract the rows with only 1 and then insert the result back

[Askic V]

In the following example, the result is expected:

A = [5 5 3 2 1 3 4 5 6 2 1 4 5]

A = 1×13

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

ind = find(A == 5) % keep track of the indices

ind = 1×4

1 2 8 13

% processing
%..........
A(ind) = [999.9, 99.9, 9.9, 0.99]

A = 1×13

999.9000 99.9000 3.0000 2.0000 1.0000 3.0000 4.0000 9.9000 6.0000 2.0000 1.0000 4.0000 0.9900

So the logic is good. Please post your code and an example where elements are placed in the wrng positions.

[Elysi Cochin]

Now its working. Thank you

Answer 2

[Voss]

A(ind1) = Anew;