How to remove lines in a .txt file?

Hello,

Basically, I have a .txt file in which I have a first string of characters, a second string of characters divided in 5 columns and finally the following lines are divided in 5 columns as well and filled with numbers.

As a scheme explains better than my bad english, the layout is the following one :

Nodal displacements (DX,DY,DZ) [Code 163] (Vibration Mode Number)

Node    Component X     Component Y     Component Z     Modulus 

11424  1          -0.1784254      -0.14097163     1.02552846  

11428  0.99940151  -0.17841142  -0.14048249  1.02487528  

11427  0.99868083  -0.17837693  -0.13998173  1.02409795  

11426  0.99781752  -0.17834243  -0.13945551  1.02317821  

11425  0.99682903  -0.17832828  -0.13891853  1.02213867  

11423  0.97537661  -0.17893241  -0.14097127  1.0016233  

11437  0.97482145  -0.17892055  -0.14049338  1.00101339

...

I'd like to develop a routine that reads and writes the .txt file to delete the two first lines of characters, i.e.,

Nodal displacements (DX,DY,DZ) [Code 163] (Vibration Mode Number)

Node Component X Component Y Component Z Modulus ,

to be able to have a 5-columns array with nothing but only numbers that I can load in Matlab...

Thanks in advance. O.

Answer 1

[Cedric]

If you read the file using TEXTREAD, you don't need to have the file truncated first, because you can tell TEXTREAD to skip a given number of header lines. Look at the doc for this function and the parameter named 'headerlines'. Example:

 [node, X, Y, Z, modulus] = textread('myFile.txt', '%f %f %f %f %f', ...
                                     'headerlines', 2) ;

If you really want to remove 2 lines from a file, you can build a solution around:

 fid = fopen('myFile.txt', 'r') ;              % Open source file.
 fgetl(fid) ;                                  % Read/discard line.
 fgetl(fid) ;                                  % Read/discard line.
 buffer = fread(fid, Inf) ;                    % Read rest of the file.
 fclose(fid)

 fid = fopen('myFile_truncated.txt', 'w')  ;   % Open destination file.
 fwrite(fid, buffer) ;                         % Save to file.
 fclose(fid) ;

[Olivier]

It worked great! Thank you.

[Ahmad Vasel]

Very smart, the only problem is that it does not remove empty spaces below header. Can you assist me with this issue? I need to remove empty spaces too. Thanks.

[Anna]

How do I repeat this for every .txt file in the folder without manually typing the names in?

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

Answer 2

[Hazem]

My favorite solution is this (start at line 2, col 0):

    M = dlmread('filename.txt', ' ', 2, 0)

https://www.mathworks.com/matlabcentral/answers/9060-how-to-skip-the-first-line-of-a-text-file-when-reading-it

Answer 3

[Tobias]

I have been given the following code by a teacher at university:

function allData =ReadVerTxtData(filename,NumVar)
fid=fopen(filename,'r');
tline1 = fgetl(fid);    %%Vernier Format 2
tline2 = fgetl(fid);    %Untitled.cmbl 4/7/2008 20:19:02 .
tline3 = fgetl(fid);    %Latest
tline4 = fgetl(fid);    %Time  Potential
tline5 = fgetl(fid);    %t  Pot
tline6 = fgetl(fid);    %s  V
tline7 = fgetl(fid);    %
tline8 = fgetl(fid);    %0  7.60683760684
allData=fscanf(fid,'%f',[NumVar,Inf]);  %
fclose(fid);

It reads data from a text file and ignores the first 8 lines. You could add and delete lines as you desire.

Edit: I should probably add that the two inputs of the function is: your file directory + name AND the number variables / lines you want printed into matlab, 5 in your case.

[Olivier]

Thank you for your answer :)

[Simon Kumm]

Note your "allData" dimensions. Maybe you got to transpose!