How to group an array and then replace each group with different numbers?

1 view (last 30 days)
Example of array: A = [1 1 1 0 0 0 1 0 0 1 0 1 1 0 0 ];
Wanted array: B = [1 1 1 4 4 4 1 5 5 1 6 1 1 3 3];
Is is possible to separate each group of zeros in A and then replace each group with a number in another array?
First group of zeros is the first three zeros in A, g1=[0, 0, 0];
Second group: g2=[0, 0];
and so on.
Then i want to replace each group with C = [4, 5, 6, 3];
The result will be g1 = [4, 4, 4], g2 = [5, 5] and so on.

Accepted Answer

Andrei Bobrov
Andrei Bobrov on 20 Mar 2019
B = A;
B(A==0) = repelem(C,diff(reshape(find(diff([1,A,1]) ~= 0),2,[])));

More Answers (1)

Luna
Luna on 20 Mar 2019
Try this:
A = [1 1 1 0 0 0 1 0 0 1 0 1 1 0 0];
C = [4, 5, 6, 3];
A(end+1) = 1;
locRise = find([0 diff(A == 0) > 0]);
locFall = find([diff(A==0) < 0 0]);
for i = 1:numel(locRise)
A(locRise(i):locFall(i)) = C(i);
end
A(end) = [];
Note: number of groups of zeros should be same with the length of C.

Categories

Find more on Operators and Elementary Operations in Help Center and File Exchange

Community Treasure Hunt

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

Start Hunting!