Why does contains(var1, var2) find matches in two different string arrays?

4 views (last 30 days)
I have two string arrays, var1 and var2. When I use the contains function, I get a match, despite these two strings having zero common values.
String 1:
ch_names = {'FP1','FPz','FP2','AF7','AF3','AF4','AF8','F7','F5','F3',...
'F1','Fz','F2','F4','F6','F8','FT7','FC5','FC1','FC2','FC6','FT8',...
'T7','C5','C3','C1','Cz','C2','C4','C6','TP7','CP3','CP1','CP2',...
'CP4','TP8','P7','P5','P3','P1','Pz','P2','P4','P6','P8','PO7',...
'PO3','PO4','PO8','O1','Oz','O2','Iz'};
String 2:
MEG_ch = {'EOG061','EOG062','ECG063','STI101','STI201','STI301',...
'MISC201','MISC202','MISC203','MISC204','MISC205','MISC206','MISC301',...
'MISC302','MISC303','MISC304','MISC305','MISC306'};
Code used to compare the variables:
contains(string(MEG_ch), string(ch_names))
% Output:
%
% ans =
% 1×18 logical array
% 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1
The purpose of this code is to see if any string in ch_names (var2) occurs in MEG_ch (var1). If it does occur, then var1 gets categorized a certain way.
Also, if i switch var2 and var1's position in the contains function, I get the expected behavior of no matches. i.e contains(string(ch_names), string(MEG_ch)).
If there are more efficient ways to do this or I can explain a certain point in more detail, I welcome your suggestions.

Accepted Answer

madhan ravi
madhan ravi on 6 Mar 2021
ch_names = {'FP1','FPz','FP2','AF7','AF3','AF4','AF8','F7','F5','F3',...
'F1','Fz','F2','F4','F6','F8','FT7','FC5','FC1','FC2','FC6','FT8',...
'T7','C5','C3','C1','Cz','C2','C4','C6','TP7','CP3','CP1','CP2',...
'CP4','TP8','P7','P5','P3','P1','Pz','P2','P4','P6','P8','PO7',...
'PO3','PO4','PO8','O1','Oz','O2','Iz'};
MEG_ch = {'EOG061','EOG062','ECG063','STI101','STI201','STI301',...
'MISC201','MISC202','MISC203','MISC204','MISC205','MISC206','MISC301',...
'MISC302','MISC303','MISC304','MISC305','MISC306'};
any(ismember(ch_names, MEG_ch)) % any matches at all 0 means false and vice versa
ans = logical
0
  3 Comments

Sign in to comment.

More Answers (0)

Categories

Find more on Data Types in Help Center and File Exchange

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!