Scaning a txt file

Hello!

I want to read specific data from several txt files (result from a AVL simulation ) and later plot that information into a table and a 3D graphic. The problem is that the information in the txt file is not "organized". I want to get the values of the Engine speed, the BMEP and BSFC. Attached is one of the 17 txt files. They are all the same, only the values change in function of the engine speed.

Answer 1

[Mathieu NOE]

hello Carolina

this code will scan the file and search for the targeted variables

you can expand (add more variables) if you wish

it will retrieve associated numerical data , whatever the dimensions (width) of the data

hope it helps

Filename = 'Case_1.txt';
fid = fopen(Filename);
tline = fgetl(fid);

while ischar(tline)
    
    if contains(tline,'Engine Speed :')   
        tmp = strtrim(regexp(tline, '\s+', 'split'));   %split by spaces
        dd = regexp(tmp,'-?[0-9]+.[0-9]+', 'match'); % extract numeric parts only inside the cell (in case of mix with text)
        str_temp = strjoin( cat(2,dd{:}), ',') ;    % Transform a cell array of cell arrays into string / delimiter = blank or comma
        Engine_Speed = str2num(str_temp); % convert string to num

    end
    
   
    if contains(tline,'BMEP [bar]')   
        tmp = strtrim(regexp(tline, '\s+', 'split'));   %split by spaces
        dd = regexp(tmp,'-?[0-9]+.[0-9]+', 'match'); % extract numeric parts only inside the cell (in case of mix with text)
        str_temp = strjoin( cat(2,dd{:}), ',') ;    % Transform a cell array of cell arrays into string / delimiter = blank or comma
        BMEP = str2num(str_temp); % convert string to num

    end

    if contains(tline,'BSFC [g/kWh]')   
        tmp = strtrim(regexp(tline, '\s+', 'split'));   %split by spaces
        dd = regexp(tmp,'-?[0-9]+.[0-9]+', 'match'); % extract numeric parts only inside the cell (in case of mix with text)
        str_temp = strjoin( cat(2,dd{:}), ',') ;    % Transform a cell array of cell arrays into string / delimiter = blank or comma
        BSFC = str2num(str_temp); % convert string to num
    end
    
    
tline = fgetl(fid);
    
end

fclose(fid);

[Mathieu NOE]

a better implementation - as we always do the same processing , so let put these 4 lines in a function and make the code more concise and readable

Filename = 'Case_1.txt';
fid = fopen(Filename);
tline = fgetl(fid);

while ischar(tline)
    
    if contains(tline,'Engine Speed :')   
        Engine_Speed =  do_stuff(tline);
    end
   
    if contains(tline,'BMEP [bar]')   
        BMEP = do_stuff(tline); 
    end

    if contains(tline,'BSFC [g/kWh]')   
        BSFC = do_stuff(tline);
    end
    
tline = fgetl(fid);
end

fclose(fid);

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function out = do_stuff(tline)
        tmp = strtrim(regexp(tline, '\s+', 'split'));   %split by spaces
        dd = regexp(tmp,'-?[0-9]+.[0-9]+', 'match'); % extract numeric parts only inside the cell (in case of mix with text)
        str_temp = strjoin( cat(2,dd{:}), ',') ;    % Transform a cell array of cell arrays into string / delimiter = blank or comma
        out = str2num(str_temp); % convert string to num
end

[Carolina Maria Clase Sousa]

It worked!!! Thanks!

[Mathieu NOE]

Glad it helped !