Access the array index using find

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Hello ,
I have an array A1 = [1 12 23 45]; and
second array A1_1 = [45 23];
I need to find the index of 45 and 23 in first array A1. I am using following function to do this find(a==a_1(1)) --Output =4 find(a==a_1(2)) --Output =3 I want to get this for multiple elements of array .
It would be grateful if you let me know the changes that are to be done to get it for multiple elements in an array.
Looking forward to hear from you at the earliest.
Thanks Pankaja

Accepted Answer

Azzi Abdelmalek
Azzi Abdelmalek on 2 Jul 2015
Edited: Azzi Abdelmalek on 2 Jul 2015
a= [1 12 23 45];
b= [45 23]
out=arrayfun(@(x) find(a==x),b,'un',0)
Or using a for loop. The previous answer, also uses a loop.
for k=1:numel(b)
out{k}=find(a==b(k));
end

More Answers (1)

Titus Edelhofer
Titus Edelhofer on 2 Jul 2015
Hi,
I guess you are looking for this:
A1 = [1 12 23 45];
A1_1 = [45 23];
[~,idx] = ismember(A1_1, A1)
idx =
4 3
Titus
  2 Comments
Azzi Abdelmalek
Azzi Abdelmalek on 2 Jul 2015
What if A1 = [1 12 45 23 45]?
Titus Edelhofer
Titus Edelhofer on 2 Jul 2015
Yes, you are right. In this case you would find only the first of the two 45 ...

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