I have an array a = [6 8 2 1 9] and b = [1 2 6]. I want a function which returns 2 since a(2)=8 which is the smallest element of a not in b.
What I have tried so far:
[A,I] = sort(a);
index = I(find(~ismember(A,b),1))
I would like something faster as this piece of code has to run many times and the arrays involved are very large.
Thanks in advance!
Another (faster, I believe) solution would be:
a = [6 8 2 1 9];
b = [1 2 6];
[d,I] = setdiff(a,b); % d is the set difference, I is the indices of d elements in a
[m,J] = min(d); % m is the minimum in d, J is it's index
I(J) % This is the index of m in d (the value that you want)
ans =
2
Does this do what you need?
>> a = [6 8 2 1 9];
>> b = [1 2 6];
>> min(a(~ismember(a,b)))
ans =
8
Edit:
Oops - I meant
>> find(a==min(a(~ismember(a,b))),1)
ans =
2
This finds the index as you requested, rather than the value, which the first answer gives.
setdiff