Find set of all adjacent points that are close to each other

I would like to find in Y[n] a set of adjacent points that are close to each other, but I don't get all the desired points. For example.

Y = [ 1.1  1.12    9.2    8.3  8.295  8.292     4.1  4.12    4.19];
dY_idx = find(abs(diff(Y)) < 0.022);
Y_adj_close = Y(dY_idx)

This code results in:

Y_adj_close =
    1.1000    8.3000    8.2950    4.1000

But I would like the result to be:

Y_adj_close =
    1.1000  1.1200     8.3000  8.2950  8.2920   4.1000  4.12 

How can I get the desired result? (Note: I probably could also do a Y = fliplr(Y) followed by a second round and then combine results to get all the unique points, but that would be two sets of operations on a large vector. Hoping for a faster solution.)

Answer 1

[Tommy]

How about this?

logidx = abs(diff(Y)) < 0.022;
Y_adj_close = Y([logidx 0] | [0 logidx]);

Y_adj_close =

    1.1000    1.1200    8.3000    8.2950    8.2920    4.1000    4.1200

[Paul Hoffrichter]

Thank you very much. I see that a zero at the beginning shifts the logical 1's over to get the last adjacent point of each close set of points; and the or'ing keeps the original logidx finding. I appreciate your help.

[Tommy]

You're very welcome, happy to help!

[Paul Hoffrichter]

My new question deals with my need to keep dimension of x and y the same. I forgot to mention that in this question. I used your answer here to work out an answer that works. Just wondering whether it can be modified to perform better.

https://www.mathworks.com/matlabcentral/answers/543197-plot-only-adjacent-points-that-are-close-to-each-other

Just using plot in the question to ensure dimensions match, and provide a quick sanity check.