loop over struct with multiple functions

Dear MATLAB Community,

I have the following problem:

I need to extract 2 specific numbers from pretty large txt files from a specific line. The line(s) is (are) not the same for each txt file. Also in some txt files there is only one line of interest.

I have written the following code to extract the numbers I am interested in from one (manually) entered txt file. In total I have (in the case of a txt file with 2 lines of interest) 4 variables (cal1avg, cal1max, cal2avg, cal2max) which correspond to the 2 numbers per line (4 because there are 2 lines with 2 numbers each). In case of only one line of interst I have set up an if clause that sets the values of the other 2 numbers from the missing line to 0 .

this works, so far so good.

now I want to loop this procedure over many txt files. I imported the txt files into a struct. I want to loop the procedure mentioned over all files from the struct. I further want to add new "collumns" to the struct, one collomn for each variable (cal1avg, cal1max,...).

I tried it without the if function to see if that even works - it does not.

my endproduct should be similar to the following

collumns: filename | cal1avg | cal1max | cal2avg | cal2max (the other collums from the struct don't matter)

here the code for manually entered files (works)

%%extract validation info from one file%%

%enter filename
%note: if you have more (or less) than 2 validations per .txt file you need.
%to adapt the code at the marked spot

text = fileread('001_p2_2021-03-11_11-17-21_Session_Data.txt');
TextAsCells = regexp(text, '\n', 'split');

%search for the line(s) of interest
mask = ~cellfun(@isempty, regexp(TextAsCells, '!CAL VALIDATION HV9 L LEFT'));
line = TextAsCells(mask);

%if there is only one line of interst
if size(line) == [1 1]

   cal1 = regexp(line{1,1}, '(-)?\d+(\.\d+)?(e(-|+)\d+)?','match');
   %avg is always the 3rd element in the cell
   cal1avg = cal1{1,3};
   %max is always the 4th element in the cell
   cal1max = cal1{1,4};

   cal2avg = 0;
   cal2max = 0;
   
%if there are two lines of interest
else if size(line) == [1 2]

    cal1 = regexp(line{1,1}, '(-)?\d+(\.\d+)?(e(-|+)\d+)?','match');
    cal2 = regexp(line{1,2}, '(-)?\d+(\.\d+)?(e(-|+)\d+)?','match');
    
    cal1avg = cal1{1,3};
    cal1max = cal1{1,4};
    cal2avg = cal2{1,3};
    cal2max = cal2{1,4};
    
%if something went wrong, i.e. the worng line is chosen
else
    disp("error")
    end
end

code from the loop I tried to code (does not work) (no error, just nothing happens)

data = dir('*.txt');   

for i = 1:length(data)
   
    file = data(i).name;
    
    text = fileread(file);
    
    TextAsCells = regexp(text, '\n', 'split');
   
    mask = ~cellfun(@isempty, regexp(TextAsCells, '!CAL VALIDATION HV9 L LEFT'));
    line = TextAsCells(mask);

    cal1 = regexp(line{1,1}, '(-)?\d+(\.\d+)?(e(-|+)\d+)?','match');
    cal2 = regexp(line{1,2}, '(-)?\d+(\.\d+)?(e(-|+)\d+)?','match');

    data(i).cal1avg = cal1{1,3};
    data(i).cal1max = cal1{1,4};
    data(i).cal2avg = cal2{1,3};
    data(i).cal2max = cal2{1,4};

end

I can't share the txt file(s) because they include personal data from the experiment (btw these are eye-tracker data). The files contain text and numbers and they are pretty random (so no matrix or sth). The goal is to show the 4 values (cal1avg, cal1max, ...) for each filename.

Help would be awesome!

Thank you very much!

Best,

Tim

[J. Alex Lee]

does your call to "dir" return results?

also you may want to look into the "table" data type

[Tim Dreßler]

Yes my dir() give me all the files in the directory in a struct (see screenshot). Also note the in the screenshot I only imported 10 files as a test (there are over 400 .txt files in total).

With the screenshot I can also make clear where I want the 4 variables (cal1avg, ...) to be (see screenshot).

It would be also fine if the data is written in a (new) table. The main goal is to have filename and cal1avg, cal1max, cal2avg and cal2max in one file/structure/table with the variables obviuously corresponding to the file they came from.

[Stephen23]

If that loops runs then the fields CAL1AVG etc. should be defined, but I don't see them in your screenshot. Some ideas for debugging this:

• check the loop counter: what value does it have?
• check the values of MASK and LINE (you should change this name to avoid masking the inbuilt LINE function).
• check the content of the files: do they really contain that text?

Note that you can use READLINES and CONTAINS to simplify your code. Also note that

else if

should be

elseif

[Jiri Hajek]

Hi, it's really difficult to understand what exactly is your problem. Did you try to debug the code using a breakpoint and stepping through the individual commands? Please tell us, which line of your code does not produce the desired result...

[Tim Dreßler]

Hey, thank you for all your help. I figured out what the porblem is and it work now how I want it to.

Thank you for your help!