Reading .txt files and replace numbers from one file to another

14 次查看（过去 30 天）

显示更早的评论

Ivan Mich 2020-4-5

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/515574-reading-txt-files-and-replace-numbers-from-one-file-to-another

评论： Ivan Mich 2020-4-6

采纳的回答： Geoff Hayes

Hello, I have a problem with a code.

First of all I have two .txt files, file1.txt and file2.txt.

File1 has 2 columns with 3 lines, and File2 has 5 columns with 20 lines. I would like to read this files and after that I would like to take the two numbers of the first line of File1.txt and replace these two numbers to the column 3 and column 4 of the first line of the File2.txt.

I try to create a loop, but I can not understand how to create this code.

Could anyone help me?

2 个评论
显示无隐藏无

Geoff Hayes 2020-4-5

Ivan - please post the code that you have written so that we can help you understand what isn't working with the code.

Ivan Mich 2020-4-5

编辑：Geoff Hayes 2020-4-5

my code is incomplete because I don't understand how I can get specific data from the file so I'm confused.

clc
clear
file1=fileread('file1.txt')
file2=fileread('file2.txt')
filenameB = 'file2.txt';
outfilenameB = 'file2.txt';
LineToChange1 = 5;
NewContent1 = ' .....';
S = fileread(filenameB);
SS = regexp(S, '\r?\n', 'split');
SS{LineToChange1} = NewContent1;
fid = fopen(outfilenameB, 'w');
fprintf(fid, '%s\n', SS{:});
fclose(fid);

the point is that I would like to replace the values of 3rd nad 4th column of the first line of file2.txt (521 625 in file2.txt) with the values of the first line in file1.txt (6.4 30 in file1.txt). I think i should use a loop with for but i can not compose my code. I sent you these files for your facilitation.

Thank you in advance

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Geoff Hayes 2020-4-5

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/515574-reading-txt-files-and-replace-numbers-from-one-file-to-another#answer_424199

Ivan - try using importdata to read your text files, perhaps something like

file1Data = importdata('file1.txt', ' ', 1); % skip the header row
file2Data = importdata('file2.txt');

Now you have two matrices and so you should be able to access the appropriate rows of either to do whatever changes are necessary. You can then write out the results back to file with writematrix or equivalent.

11 个评论
显示 9更早的评论隐藏 9更早的评论

Geoff Hayes 2020-4-6

编辑：Geoff Hayes 2020-4-6

why are you using three types of file reading function?

file1=importdata('file1.txt');  % <---- importdata
X=file1.data(:,1);
R=file1.data(:,2);
file2='_tst_C_.params'
ex=readfile(file2)'             % <---- readfile - does this exit??
filename=file2
outfilename2 = 'new.params';
LineToChange = 9;
NewContent = X R;
S = fileread(filename);         % <---- fileread

I don't understand what you mean by

I would like to replace line number 9 in file2 by importing the first line from the file1.txt. After that I would like to replace line number 9 in file2 by importing the second line from the file1.txt. And last I would like to replace line number 9 in file2 by importing the third line from the file1.txt.

Why do you want to replace line 9 (of file 2) with line 1 (of file 1), then line 2 (of file 1) and then with line 3 (of file 1)? Do you want to write to a new file each time you update this line? Which columns of line 9 do you want to change, 3 and 4 still, or has that changed?

file1Data = importdata('file1.txt', ' ', 1); % skip the header row
file2Data = importdata('file2.txt');
for k = 1:size(file1Data,1)
    file2Data(9,3:4) = file1Data(k,1:2);
    % do something??
end

Geoff Hayes 2020-4-6

Is the line of File1.txt a string? Are the strings in each line of File2.txt the same length? Please illustrate with an example of what you want to do...

Ivan Mich 2020-4-6

I am uploading the two files in order to understand what I want to do. in these files, I would like to replace line 3 from File2 once with the first line of File1, once with the second line of file1 and once with the third line of File1.

I have to mention that i use readfile('File2.txt') in order to read this file.

请先登录，再进行评论。