How can I find name in a matrix or an array?

Question

M G 2011-5-30

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/8425-how-can-i-find-name-in-a-matrix-or-an-array

采纳的回答： Oleg Komarov

在 MATLAB Online 中打开

Hey Matlab users, Suppose we have an array:

{channel_name.labels}

which refers to:

ans =

Columns 1 through 14
    'Fp1'    'Fp2'    'F3'    'F4'    'C3'    'C4'    'P3'    'P4'    'O1'    'O2'    'F7'    'F8'    'T7'    'T8'

Suppose the array is much bigger than this and finding a particular name is really time consuming. I used 'Find' command but maybe I cannot use it properly and it didn't work. How can I find athe row and column of a particular name let's say 'P4'?

I thank you very much in advance :)

Mehdi

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Answer 1

Oleg Komarov 2011-5-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/8425-how-can-i-find-name-in-a-matrix-or-an-array#answer_11607

在 MATLAB Online 中打开

c = {'Fp1','Fp2','F3','F4','C3','C4','P3'
     'P4' ,'O1' ,'O2','F7','F8','T7','T8'};
idx = strcmpi('O1',c);

where idx is a logical array (same dim as c) that is true (1) where 'O1' is found in c.

To get the row and the column with find:

[r,c] = find(idx);

If you need r and c to retrieve O1 or to use them on an array the same dimension as c then I suggest to use idx. It is preferred in terms of performance to use logical indexes and to avoid calling find.