Read matrix from a txt file after a specific expression

Hello i m new with matlab, i need to read in a text file after a specific expression 'This section' and 3 header lines (A, B and C) a matrix with 3 colones and 10 rows

This section

A

B

C

 1   23.0 5.33

 2   12.4 6.07

 10  22.4 64.07

[Cedric]

Is this line C constant? How does it look like? And can there be multiple 'This section' in the file?

[Lila wagou]

Tanks for the comment,The lines A, B and are not constants so i look to consider them like header lines, for the specific expression 'This section' there is one only.

[Lila wagou]

Please any suggestions ?

Answer 1

[Cedric]

You should use TEXTREAD with the 'heaerlines' parameter set to the number of lines (e.g. 3) that characterizes your header.

For example:

 >> [id,temp,press] = textread('myData.txt', '%f %f %f', 'headerlines', 3)
 id =
     1
     2
    10

 temp =
   23.0000
   12.4000
   22.4000

 press =
    5.3300
    6.0700
   64.0700

[Lila wagou]

Thanks for you Mr Wannaz, but i need to read in a text file after a specific expression 'This section' which it is not a known line position in the txt file, so i must know first its position and i count 3 headerlines and i read the matrix.

[Cedric]

Then you can tailor the following code to your needs:

 fid = fopen('data.txt', 'r') ;

 % Read lines until 'This section' found or FEOF.
 while ~(strcmpi(fgetl(fid), 'this section') || feof(fid)) end

 % Skip next 3 lines.
 fgetl(fid) ;  fgetl(fid) ;  fgetl(fid) ;

 % Read and reshape data.
 data = reshape(fscanf(fid, '%f'), [], 3).' ;

 fclose(fid) ;

Note that you should manage cases where 'This section', the three header lines, or data, are not found.

[Lila wagou]

It is perfect work, Thanks