MATLAB: Delete rows in a .txt table

MATLABtextscantxt

Dear all, i'm dealing with a problem: I have a .txt table and i want to write and delete the last n rows of this table using a condition or statement (here named solution).
here is the .txt table (shorelines.txt):
Station Profile_number shoreline_number east north distance_along_swath shoreline_elevation error analysis_type time
CLMO 5 1 681775 5955821 101.18 11.67 0.98 classic 735513.08088
CLMO 7 1 681295 5955779 197.57 50.48 4.15 classic 735513.08133
CLMO 7 2 681350 5955683 86.25 19.54 0.96 classic 735513.08154
CLMO 9 1 681116 5955539 98.12 21.44 0.67 classic 735513.08208
CLMO 9 2 681114 5955540 100.87 24.03 1.21 classic 735513.08231
CLMO 10 1 681073 5955484 82.87 19.94 0.62 stack 735513.08275
First I readed the table in this way:
clear
%load shorelines table
file=('shorelines.txt');
fid=fopen(file,'r');
i=1;
while ~feof(fid)
    %tline = fgetl(fid);
    A=textscan(fid,'%s %u %u %f %f %f %f %f %s %f\r\n','delimiter',' ','HeaderLines',1);
      for j=1:10 %number of columns (default)
          data(i,j) = A(1,j);
      end
      i=i+1;
  end
clear j i
then I create the conditions defined as:
solution==1 %delete the last three rows of the table
solution==2 %delete the two last rows of the table
solution==3 %delete just the last row of the table
i've been trying to develop a method to delete the rows but none works. For instance, i try this:
if solution==3
tline(nim)=fgetl(nim) ;
fclose(fid);   
end
but nothing happens… somebody have an idea how to deal with .txt tables? thanks a lot in advance…

Best Answer

Here is a solution assuming that my comment above under your question was correct.
% - Define run parameters.
fileLocator = 'shorelines.txt' ;
headerlines = 1 ;
nList       = [1,2,5,20] ;
% - Split input file name, read file.
[path_in,fname_in,ext_in] = fileparts( fileLocator ) ;
buffer = fileread( fileLocator ) ;
% - Find lines ends (must check wheter file ends with one and remove 
%   it from the list if present).
lineEnds = find( buffer == 10 ) ;
if buffer(end) == 10 || buffer(end-1) == 10
    lineEnds(end) = [] ;
end
% - Loop over n's.
for k = 1 : numel( nList ) ;
    % Check not case where more lines to remove than present in file.
    if numel(lineEnds)-nList(k) < 1
        fprintf( 'Skip removing %d lines, file contains only %d lines.\n', ...
            nList(k), numel(lineEnds) ) ;
        continue ;
    end
    % Compute cutoff position in buffer.
    cutoff = lineEnds(end-nList(k)+1)-1 ;
    % Build new file name.
    fname_out = sprintf( '%s_%d.%s', fname_in, nList(k), ext_in ) ;
    % Output.
    fid = fopen( fullfile( path_in, fname_out ), 'w' ) ;
    fwrite( fid, buffer(1:cutoff) ) ;
    fclose( fid ) ;
end
Note that this code is just to illustrate. To make it robust, you'll have to take in account the number of header lines in the check that the number of lines to remove doesn't exceed the number of data lines, etc.
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