How can I find a string in an array of strings? Error using strfind PATTERN must be a string scalar or character vector.

Dear all,

I am currently trying to derandomize a list of filenames. I do have a derandomization sheet for this. However, whenever I am trying to run the script I wrote for this I encounter the following error:

Error using strfind

PATTERN must be a string scalar or character vector.

Error in Derandomization (line 14)

idx = find(~cellfun(@isempty,strfind(N,C)))

This is my code:

clearvars
close all
basicpath = ('C:\path');
[~,~,raw] = xlsread('filenames_new_sheet.xlsx');
T = readtable('derandomization.xlsx');
t = T{:,'Filename'}
newStr = erase(t,'_kakaka'); %get body of filenames to match 
C = unique(newStr) % delete filenames that exist more than once
N = raw(:,2); runr
j = size(C)
k = size(N)
for n = 1:j    
for m = 1:k
idx = find(~cellfun(@isempty,strfind(N,C)))
end
end

>> class N

ans =

'char'

>> class C

ans =

'char'

Why do I keep getting this error message everytime? And what can I do to avoid it? Thank you, everyone.

Kindly

[darova]

Why do you need for loop here?

for n = 1:j    
for m = 1:k
idx = find(~cellfun(@isempty,strfind(N,C)))
end
end

[Hannah_Mad]

To iterate through the rows of the new sheet with the string variables from the derandomization sheet

[Stephen23]

"Why do you need for loop here?"

The second input of strfind is one pattern (i.e. a single character vector or string scalar), so given that C contains multiple patterns at least one loop is required here... I guess those two loops are remants of earlier experimentation.

[Hannah_Mad]

However, it works if I don't iterate through the columns, but if I copy/paste a particular example from the list - then I will get the fields where this particulare filename is found in the new sheet.

clearvars
close all
basicpath = ('C:\Hannah\Dystra_speech');
[~,~,raw] = xlsread('DDK_acoustic_durations.xlsx');

C2 = 'Filename_1_2_0'
N = raw(:,2); 
idx = find(~cellfun(@isempty,strfind(N,C2)))

like this

idx =

2

3

4

5

6

7

8

9

10

11

1702

1703

1704

1705

1706

1707

1708

1709

1710

1711

3402

3403

3404

3405

3406

3407

3408

3409

3410

3411

[Hannah_Mad]

Is there any way, I could turn my variable into a string scalar or character vector?

Thank you

[Hannah_Mad]

If I put '' around the C it will only return empty vectors

idx =

0×1 empty double column vector

[Stephen23]

@Hannah_Mad: please upload the some sample variables (e.g. raw and T) or the original files, and please show or describe the expected output for those exact variables/files.

[Image Analyst]

Hannah, again I think you misunderstood Stephen's comment. When he said "please upload the some sample variables (e.g. raw and T) or the original files" he meant to attach 'Effekte_der_DBS_korrigiert.xlsx' or 'DDK_acoustic_durations.xlsx' using the paper clip icon. And I'm not seeing those anywhere on this page on any of your posts. We'll check back later for them.

Answer 1

[Image Analyst]

Try contains(). Not sure what derandomize means. Do you mean sort according to some vector of values or alphanumerically?

[Hannah_Mad]

Well I have the Derandomization sheet where I have one column of the old filenames and the other ones are the derandomized numbers. And I want to finde the old filenames in the new sheet so that I can match them with the derandomization from the derandomization sheet.

[Image Analyst]

So, did contains() work? If not, try ismember() if you want an exact match. If ismember() doesn't work, try swapping the first and second input arguments to ismember() and try again.

[Stephen23]

Note that ismember matches the entire string, and does not search for substrings.

[Hannah_Mad]

Unfortunately it does not work as I want to search substrings.

[Image Analyst]

But Hannah, I think you misunderstood. Stephen was merely pointing out the differences between ismember() and contains(). ismember() does not search substrings, while contains() does search substrings. So again, I ask did contains() work for you?

Answer 2

[Hannah_Mad]

Thank you, contains () did work for me.