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

2 ビュー (過去 30 日間)
Hamza Imtiaz
Hamza Imtiaz 2021 年 3 月 6 日
編集済み: Hamza Imtiaz 2021 年 3 月 7 日
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.

採用された回答

madhan ravi
madhan ravi 2021 年 3 月 6 日
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 件のコメント
Walter Roberson
Walter Roberson 2021 年 3 月 6 日
'MISC202' (8th element)
'C2' (28th element of pattern)
'MISC202' contains 'C2' so so that is a match.
The contains() operator does not compare for entire strings: it compares for substrings.
Hamza Imtiaz
Hamza Imtiaz 2021 年 3 月 6 日
編集済み: Hamza Imtiaz 2021 年 3 月 7 日
Walter,
Thank you, that makes sense.

サインインしてコメントする。

その他の回答 (0 件)

カテゴリ

Help Center および File ExchangeResizing and Reshaping Matrices についてさらに検索

タグ

Community Treasure Hunt

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

Start Hunting!

Translated by