Optimization of manipulating an array

I have an array, where 0s are between non-zeros integer or floating numbers.

>> a = [1, 0, 5, 0, 6, 0, 12, 0];

I am looking to find the average of every adjacent two numbers and insert it to replace the zero between them:

like for the example above:

>> b = [1, 3, 5, 5.5, 6, 9, 12, 15]

For the last 0, we should add the difference between 12 and 9 to the last value, which is 12. So that makes (12 - 9) + 12.

I am looking for an optimized code (may be if possible without loop).

Thanks

Answer 1

[Ive J]

a = [1, 0, 5, 0, 6, 0, 12, 0];
b = a;

a_adj_mean = movmean(a(1:2:end), 2);
zero_idx = a == 0;
b(zero_idx(1:end - 1)) = a_adj_mean(2: end);
b(end) = 2*b(end-1) - b(end - 2)

b = 1×8

1.0000 3.0000 5.0000 5.5000 6.0000 9.0000 12.0000 15.0000

[Mahmood AL Imam]

Thank you very much Ive J