# Finding the indices of the elements of one array in another

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Deepa Maheshvare on 20 Jan 2022
Edited: Deepa Maheshvare on 20 Jan 2022
Given two vectors A and B,
I want to find the index of elements of B in A
I tried
A = ["G1", "V2", "G3", "G4", "V1"]
B = ["V1", "G4"];
[sharedvals,idxs] = intersect(A, B, 'stable')
The above returns
idxs =
4
5
Expected result:
idxs =
5
4
Could someone suggest how to obtain the expected result?
##### 1 CommentShowHide None
Deepa Maheshvare on 20 Jan 2022
idx = arrayfun( @(x)( find(nodes==x) ), subnodes )
works as expected, but I am not sure why the one posted above doesn't works

Rik on 20 Jan 2022
You muct have thought of this already (as it is one of your tags), but ismember does what you need:
A = ["G1", "V2", "G3", "G4", "V1"];
B = ["V1", "G4"];
[sharedvals,idxs] = ismember(B,A)
sharedvals = 1×2 logical array
1 1
idxs = 1×2
5 4
If you want a column vector you can transpose it.
##### 1 CommentShowHide None
Deepa Maheshvare on 20 Jan 2022
Ahh, thanks. I had tried [sharedvals,idxs] = find(ismember(A, B)).

R2021a

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