Find the longest sequence of consecutive non-zero values in a vector

Hello everyone, I want to know how to find in a vector the longest sequence of consecutive non-zero values. example: I have x = [0 1 2 3 0 5 6 7 8 0 10]; I must have as output the block y = [5 6 7 8] Thank you in advance.

Answer 1

[Walter Roberson]

x = [0 1 2 3 0 5 6 7 8 0 10];
zpos = find(~[0 x 0]);
[~, grpidx] = max(diff(zpos));
y = x(zpos(grpidx):zpos(grpidx+1)-2);

[Jan]

+1. This shorter than the approach with RunLength.

[Walter Roberson]

Note: the 0 before and after x in [0 x 0] are there in case the input, x, does not begin with a 0, or does not end with a 0. There are implied markers of beginning of sequence at the beginning of x and of end of sequence at the end of x.

Answer 2

[Adam]

https://uk.mathworks.com/matlabcentral/fileexchange/41813-runlength

or other similar run length functions should help, especially if you trivially binarise your input first.

[Jan]

x = [0 1 2 3 0 5 6 7 8 0 10];

[b, n, xIdx] = RunLength(x ~= 0);
xIdx         = xIdx(b);
[maxN, nIdx] = max(n(b));
r            = x(xIdx(nIdx):xIdx(nIdx) + maxN - 1)

I think, Walter's solution is nicer.