MATLAB: Using code to import data

import

I have text files that I am trying to import into MATLAB (sample attached). The text files contain data collected using sensors (named q01, q02 etc.). The first 5 lines are garbage all I really need are the lines of data after q01 and q02 (complete file has more sensors). I have 529 of these files that I am trying to read in so it is not practical to use the import tool each time. I have the file names stored in a structure (field=names). This is the code that I have tried to use to read in the data but it is not extracting all of the data.

delimeterIn=' ';
headerlinesIn=5;
%Imports data and creates a structure with separate fields for numerical
%and text data
for i=1:length(files)
    x(i)=importdata(files(i).name, delimeterIn, headerlinesIn);
end

Any help efficiently reading these files in would be appreciated.

Best Answer

If the files are all the same format, use the textscan function. No file was attached, but if one magickally appears, I will do my best to help you import the data from it. (It is possible that there are subsequent header lines embedded in the file, and that may be the reason you are not able to import the entire file. There are ways to deal with that with textscan.)

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MATLAB: How to delete repeating header lines from text file

There is no end-of-file in the file you posted. Normally, I would use this code:

fidi = fopen('Bruno Rodriguez a160628.dat','r');
k1 = 1;
while ~feof(fidi)
    data(k1) = textscan(fidi, repmat('%f',1,20), 'HeaderLines',4, 'CollectOutput',1, 'EndOfLine','\r\n');
    fseek(fidi,0,0);
    k1 = k1 + 1;
end

With the file you posted, it is necessary to detect the last record differently. I used fgetl and strfind, copying part of the last header manually to the strfind call.

This works:

fidi = fopen('Bruno Rodriguez a160628.dat','r');
lastrecord = 0;                                                                         % Initialise ‘lastrecord’
k1 = 1;                                                                                 % Initialise Counter
while ~feof(fidi)
    data(k1) = textscan(fidi, repmat('%f',1,20), 'HeaderLines',4, 'CollectOutput',1, 'EndOfLine','\r\n');
    if lastrecord                                                                       % If Previous Was ‘lastrecord’, Stop
        break
    end
    fseek(fidi,0,0);                                                                    % Restart At New Position
    firstline = fgetl(fidi);                                                            % Read First Line
    lastrecord = strfind(firstline, 'SJSU_Sodar_DiabloCanyon 06/28/2016 23:50:00');     % Find Last Record Section
    fseek(fidi, -1, 0);                                                                 % Back Up One Line So ‘textscan’ Will Read It
    k1 = k1 + 1;                                                                        % Increment Counter
end

MATLAB: How to display comments in a .dat file

Just read the first NL lines and display them

%...

[fid, message] = fopen(filename, 'rt');
for row = 1:NL
   fprintf(fgets(fid));
end
MyData = cell2mat( textscan(fid, '%f%f%f%f%f%f', 'Delimiter', '\t','headerlines',NL) ); 
%...

Best Answer

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MATLAB: How to delete repeating header lines from text file

MATLAB: How to display comments in a .dat file

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