readmatrix error: "filename" must be a string scalar or character vector.

Hi,

I am trying to run a code to import and analyze all .txt file in folder 0p0001nM. There should be 5 of them, and each one contains 4 columns of data. My goal is the following:

1. extract the third column of each file
2. Apply certain operation to the third column of files(identical operation between files)
3. Creating a matrice, which contain all 5 columns

The code is shown below. Apparently, I failed to import any data from .txt file. The errormessage is the followng:

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Error using readmatrix (line 158)

"filename" must be a string scalar or character vector.

Error in cvHistamine (line 5)

S(k).data=readmatrix(F);

----------------------------------------------------

Can anyone help to solve this problem ?

Andika

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P='C:\Users\aasyuda\Documents\CV-EIS\aptamer-histamin\14April2023\14April2023\0p0001nM';

S=dir(fullfile(P,'*.txt'));

for k=1:numel(S)

F=dir(fullfile(P,S(k).name));

S(k).data=readmatrix(F);

end

[Stephen23]

DIR returns a structure. What do you expect READMATRIX to do with a structure as its first input argument?

Answer 1

[Stephen23]

Get rid of DIR from inside the loop.

P = 'C:\Users\aasyuda\Documents\CV-EIS\aptamer-histamin\14April2023\14April2023\0p0001nM';
S = dir(fullfile(P,'*.txt'));
for k = 1:numel(S)
    F = fullfile(P,S(k).name); % get rid of DIR!!!!
    S(k).data = readmatrix(F);
end

The DIR before the loop already returns a structure listing all of the .TXT files that it can find: what do you expect calling another DIR inside the loop would achieve?