# find index conditional on two vectors

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MiauMiau on 23 Jun 2017
Commented: MiauMiau on 23 Jun 2017
Hi,
I have two vectors =
resp = [1 2 3 1 1 2 3 3 3 1];
fing = [1 2 1 2 1 1 1 2 2 1];
How do I find the indices of resp where resp ==1 and fing ==1 (for instance in this example, this would be index 1 of resp, index 5 of resp, and index 10 of resp)?
Many thanks

Edited: Adam on 23 Jun 2017
find( resp == 1 & fing == 1 );
If you don't need the actual linear indices though then the logical vector returned by just
resp == 1 & fing == 1
will work as an index into other arrays if needed and is more efficient than finding the linear indices first.
MiauMiau on 23 Jun 2017
oh my, so simple...I was trying find(resp(resp==1&fing==1)) which delivered indices of the subset. Many thanks

KSSV on 23 Jun 2017
clc; clear all ;
resp = [1 2 3 1 1 2 3 3 3 1];
fing = [1 2 1 2 1 1 1 2 2 1];
idx1 = find(resp==1)
idx2 = find(resp==2)
MiauMiau on 23 Jun 2017
?? That is not answering my question at all. Where are you making use of "fing" in your example..?