Change sequence of consecutive trues to falses, in logical array

4 views (last 30 days)
Hello guys!
I would like to find a fast procedure to change from true to false the consecutive trues in a logical array excluding only the first and the last true in the sequence.
For instance:
x=[true;false;false;true;true;true;true;true];
Desired output array should be:
output=[true;false;false;true;false;false;false;true];
Hope the question is clear.
Thank you!

Accepted Answer

Bruno Luong
Bruno Luong on 13 Oct 2022
Edited: Bruno Luong on 13 Oct 2022
x=[true;false;false;true;true;true;true;true;false;true]'
x = 1×10 logical array
1 0 0 1 1 1 1 1 0 1
x & ~([false,x(1:end-1)]&[x(2:end),false])
ans = 1×10 logical array
1 0 0 1 0 0 0 1 0 1

More Answers (1)

Chunru
Chunru on 13 Oct 2022
x=[true;false;false;true;true;true;true;true]'
x = 1×8 logical array
1 0 0 1 1 1 1 1
output = x;
dx = diff(x(1:end-1))
dx = 1×6
-1 0 1 0 0 0
output1 = output(2:end-1);
output1(output1 & (dx==0)) = false;
% Desired output array should be:
output(2:end-1) = output1;
output
output = 1×8 logical array
1 0 0 1 0 0 0 1
% Desired
[true;false;false;true;false;false;false;true]'
ans = 1×8 logical array
1 0 0 1 0 0 0 1
  1 Comment
Enrico Gambini
Enrico Gambini on 13 Oct 2022
Thank you for the answer!
It does not work if a false is present after the last true of each sequence, for instance, if I had a vector like this:
x=[true;false;false;true;true;true;true;true;false;true]'
x = 1×10 logical array
1 0 0 1 1 1 1 1 0 1
output = x;
dx = diff(x(1:end-1))
dx = 1×8
-1 0 1 0 0 0 0 -1
output1 = output(2:end-1);
output1(output1 & (dx==0)) = false;
% Desired output array should be:
output(2:end-1) = output1;
output
output = 1×10 logical array
1 0 0 1 0 0 0 0 0 1
%Desired should be
[1,0,0,1,0,0,0,1,0,1]
ans = 1×10
1 0 0 1 0 0 0 1 0 1
I really need to automate this procedure and be sure it is robust, since I am dealing with very large array.
Thank you

Sign in to comment.

Categories

Find more on Multidimensional Arrays in Help Center and File Exchange

Products


Release

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!