Reading/writing in data from set of text files in loop

Question

Thomas Rogers 2019-5-18

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回答： Sulaymon Eshkabilov 2019-5-20

test 1.txt

I have ten text files, each containing a column of data I wish to read in matlab to arrange in a matrix. The files I am reading are named "test 1.001" "test 1.002" through *.010. Of note is that the test number changes as well (test 1 -> test 2... etc). I have managed to write some code that reads in the text files for one test, but I want to be able to expand this to read in the corresponding files for any test number. I was wondering if there was a way to condense what I have into a loop statement to make this possible?

I have attached a sample test text file and a portion of the code I have to show what I have done. (File paths and some names are changed for representation)

%%%%%%%%
%Portion of code I use
%sample_stopcount and lopoff are values I calculate in another part of code, but should be the same across all data files
Mydata = zeros(100000, 10);
filename = fullfile('C:/Users/me/Documents/MATLAB/test 1.001');
fid = fopen(filename, 'r');
data1 = textscan(fid, '%f', sample_stopcount, 'Headerlines', lopoff);
%start reading data at the 1035th line in file
Mydata = data1{1}; % takes data and puts into #x1 matrix
fid = fclose(fid);
filename2= fullfile('C:/Users/me/Documents/MATLAB/test 1.002')
fid = fopen(filename2,'r')
data2 = textscan(fid, '%f', sample_stopcount, 'Headlines', lopoff);
Mydata2 = data2{1};
fid=fclose(fid);
%
%
%continues on for Mydata10
final = [Mydata Mydata2 Mydata3 etc]
%Want to condense this into a loop and make the fullfile read in for a changing file name and extension

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Answer 1

Raj 2019-5-20

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编辑：Raj 2019-5-20

在 MATLAB Online 中打开

You can use 'sprintf' command in a loop to achieve this. Something like this:

Mydata = zeros(100000, 10);
for i=1:1 % Number of test1->test2 set of files
    for j=1:10 % Number of test 1.001->test 1.002 set of files
        k=i+(j/1000);
        myfilename= sprintf('test %f.txt',k);
filename = fullfile('C:\','Users','me','Documents','MATLAB',myfilename);
fid = fopen(filename, 'r');
Mydata(:,j) = textscan(fid, '%f', sample_stopcount, 'Headerlines', lopoff);
%use the index i to create multiple 'Mydata' when reading test1->test2 etc.
fid = fclose(fid);
    end
end

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Answer 2

Sulaymon Eshkabilov 2019-5-20

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在 MATLAB Online 中打开

Hi Thomas,

yes, it is feasible and your import code with loop would be of this format, e.g. your data *.txt files called 1.txt, 2.txt, 3.txt ... 10.txt or text1.txt, text2.txt, ....

clear variables
N_sets  = 10; % 10 files
Nheader = 10; % 10 lines of headerlines
for ii = 1:N_sets
    Name = strcat(int2str(ii), '.txt'); % DATA files called: 1.txt, 2.text, etc.// strcat('text',int2str(ii), '.txt')
    FID  = fopen(Name, 'r+');
    DATA = textscan(FID, '%f', 'headerlines', Nheader);
    A(:,ii)  = DATA{1,1};               % ALL data from Column 1
    fclose(FID);
end