Finding second smallest element in a row.

I have a row

X = [441 137 594 507 417 581 312 362 263 151 472 512 129 70 298 255 442 574 289 157 0];

I want to find the second smallest (non zero) element from X along with the column number.

Answer 1

[Azzi Abdelmalek]

X = [441 137 594 507 417 581 312 362 263 151 472 512 129 70 298  255 442  574 289  157 0];
out=min(setdiff(X,min(X)))

or

M=sort(X)
out=M(2)

[Ananya Malik]

I also wand the index of the element. i.e the column of occurrence.

[Azzi Abdelmalek]

X = [441 137 594 507 417 581 312 362 263 151 472 512 129 70 298  255 442  574 289  157 0];
[out,idx]=sort(X)
val=out(2)
index=idx(2)

Answer 2

[Guillaume]

If by 2nd smallest you mean 2nd smallest distinct value:

A = [1 0 1 2 1 4 2 3];
uA = unique(nonzeros(A)); %does sorting and remove duplicates
small2distinct = uA(2)

If by 2nd smallest you do mean 2nd smallest, so if the minimum is repeated twice, you do want the minimum:

A = [1 0 1 2 1 4 2 3];
sA = sort(nonzeros(A)); %then use plain sort
small2 = sA(2)

So, nonzeros to get all the non zero values, then sort or unique to sort the values, then take the 2nd one.