Hey,

dlmread to read out the data, modify it in Matlab, and then use dlmwrite to write it back. dlmread allows you to define where to start reading in your case the row offset would be 1.

The dlmwrite function provides you options which allows you to append the data or define the row and column you want to start writing the data back, again row offset would be 1 in your case.

See the documentation

https://de.mathworks.com/help/matlab/ref/dlmread.html

https://de.mathworks.com/help/matlab/ref/dlmwrite.html

Good luck

Hey,

dlmread to read out the data, modify it in Matlab, and then use dlmwrite to write it back. dlmread allows you to define where to start reading in your case the row offset would be 1.

The dlmwrite function provides you options which allows you to append the data or define the row and column you want to start writing the data back, again row offset would be 1 in your case.

See the documentation

https://de.mathworks.com/help/matlab/ref/dlmread.html

https://de.mathworks.com/help/matlab/ref/dlmwrite.html

Good luck

Dear Azade Jamshidi,

you can use "load" command to assign your data to a variable in the MatLab workspace (https://www.mathworks.com/help/matlab/ref/load.html).

After that you may define a starting row, let's say s_row = 2 and a final row, f_row = 40. Then you can store the data separately in another variable, for example stored_data = (s_row :f_row ,:). Finally, you can export the desired data to another file by following the procedure described here:

https://in.mathworks.com/help/matlab/import_export/write-to-delimited-data-files.html

Regards,

Anargyros

I think that the easiest way is to define a matrix using

f=load('yourfilename.txt')

then you have a matrix that you can do anything with it.

Thanks for reply dear Daniel !

I tried with below code:

.................................

x=4; % i want to change values grater than 0 to 4.

M= dlmread('my text file name.dsp','',1,0); %% .dsp is my file extension that is readable with notepad.

M(M>0)=x;

dlmwrite('my text file name.dsp',M,'delimiter','\t','precision','%.6f','roffset',1);

.................................

After this, I used the command of "type my text file name.dsp " for displaying content of written text file. It displayed a matrix 44*10 in the command window (MATLAB).

It was good, but when I opened my text file with Notepad, it has not a correct arrangement. My means is that it was not in accordance with the main file (44rows*10columns).

I attached my final notepad file for completing my description.

Do you have any idea for fixing this?

The best

Azade

Dear Daniel,

Let me say that I read the lines of 2 to 44 my text file and wrote again. This approach did not allow the first line ( in main file) to be also written in the modified file.

My other question is ;

How be writing done so that the first line in the main file to be transferred without the change into the modified file (after writing)?

Note that the first line contains several string and numeric characters.

Thank you for your time.

Azade

Dear Tamir Shaqarin ,

Thanks for your reply,

I tried it but this method was not appropriate for me.

Because the number of columns in fist row is not equal with other in my file, the following error will occur :

[Error using load

Number of columns on line 2 of ASCII file 5.dsp must be the same as previous lines.]

Dear Anargyros A. Karakalas ,

Thanks for your reply,

I will check this method soon.

The Best

Dear Azade

To write and read a text file in matlab you need to use the following structure:

for writing a text file ->

Fid=fopen(‘your_file.txt’,’w’)

fprintf(fid,’ example text ‘);

fclose(fid)

For reading a text file ->

X=regexp(fileread([cd ‘\fileName.txt’]),’\n’,’split’);

fid=fopen(’newFile.txt’,’w’);

fprintf(fid,’%s \n’,X{2:44});

fclose(fid)

Dear Azade

I have written some dozen lines of MATLAB code which can help you. Please find the code in the attachment.