How to take a data form text file to put it in another file?

Hi,
I have a text file called File.1.node which contain such as:
45 12 7 1 ( first line )
1 2 1 1
2 3 2 1
3 4 5 1
.....
% File.1.node is complete (last line )

I want to take the data from File.1.node without first line and last line, to put it in another file named Node.dat.
But How i write a code for this problem?
Thanks in advance.

Answer 1

[Star Strider]

Try this —

fidi = fopen('File.1.node','rt');

F1c = textscan(fidi, '%f%f%f%f', 'HeaderLines',1, 'CollectOutput',1);

fclose(fidi);

F1 = cell2mat(F1c);

dlmwrite(F1, 'Node.dat')

.

[Yamina chbak]

Yes it works, I get the error in last line : Error using dlwrite FILENAME must be.....

So I just write a sample code:

 fid=fopen(['Nodes.dat'],'w');
 For i=1:size(F1,1)
    fprintf(did, '%d %d %d %d\n',F1(i,1),F1(i, 2),F1(i,3), F1(i, 4));
  end

Then, I get what I want exactly. Thanks you.

[Stephen23]

"I get the error in last line : Error using dlwrite FILENAME must be....."

Because the order of deprecated DLMWRITE's inputs is wrong: the filename must come first:

dlmwrite('Node.dat', F1)

Note that your code can be improved by removing the loop and the superfluous square brackets:

fid = fopen('Nodes.dat','wt');
fprintf(fid, '%d %d %d %d\n',F1.');
fclose(fid);

Do not forget to call FCLOSE afterwards.

[Star Strider]

@Stephen — Thank you.

The other answer was originally accepted, and I deleted my original (correct) answer as the result. I got an e-mail requesting that I re-post it so that it could be accepted. I did it from memory, and did not remember the correct argument order to dlmwrite (correct in my original answer) because I rarely used it even before writematrix appeared. (My original answer used readmatrix and writematrix, however A Achbak does not have access to them. The dlmwrite call appeared in a subsequent Comment.)

[Yamina chbak]

Yes, I understand that now, well when I used dlmwrite (filename must be come first), it gives me a data but not form a matrix ( it was like : 1,2,1,1 2,3,2,1 .... ) So I prefer use @Stephen's code (removing the loop and the superfluous square brackets). Thanks you @Stephen.

Answer 2

[David Hill]

See what readmatrix gives you

m=readmatrix('File.1.node.txt');
m(1,:)=[];
writematrix(m,'Node.dat');

If you do not attach the file, we cannot test.

[Yamina chbak]

Thanks you @David Hill for answer, I did it but I get the error. You can see my comment above what is the error.

[David Hill]

what about textread()? what do you get?

m=texread('File.1.node');

[Yamina chbak]

I get the error :

 Undefined function or variable " texread"
 

I have the old version Matlab (R2018b).

[David Hill]

What about this?

m=dlmread('File.1.node',' ',[1 0 592 3]);

[Yamina chbak]

Yes It's working now ! it can read the first raw. Thanks you so much @David Hill.

But, i just checked that it gives me a wrong data, so i just say myself maybe my text file is not organize to know where is the raw and the colone o the matrix.

Thanks you again @David Hill.