find first& end of array

Hi

S=[ 0 1 5 2 0 0 0 9 3 50 53 0 0 5 7 4] ;

And I want to pick first&last number of continued numbers except 0.

Like in S ->1 ,2 ,9,53, 5,4

Are there any good method?

Thank you.

Answer 1

[Stephen23]

S = [0,1,5,2,0,0,0,9,3,50,53,0,0,5,7,4]

S = 1×16

0 1 5 2 0 0 0 9 3 50 53 0 0 5 7 4

X = diff([0;S(:)]==0)<0 | diff([S(:);0]==0)>0;
V = S(X)

V = 1×6

1 2 9 53 5 4

Answer 2

[the cyclist]

I expect someone will post a more elegant method, but I think this does what you want

S=[0 1 5 2 0 0 0 9 3 50 53 0 0 5 7 4];

first = S(diff([0 S]) == S & S~=0);
last  = S(diff([S 0]) ==-S & S~=0);

firstLast = [first; last];

output = firstLast(:)'

output = 1×6

1 2 9 53 5 4

Answer 3

[Image Analyst]

Here's a different way:

S=[0 1 5 2 0 0 0 9 3 50 53 0 0 5 7 4];
S2 = [0,S,0];
indexes = sort([strfind(S2~=0, [0 1]) + 1, strfind(S2~=0, [1,0])])

indexes = 1×6

3 5 9 12 15 17

S3 = S2(indexes)

S3 = 1×6

1 2 9 53 5 4