read files in a directory

I have to read data files in a directory. The asc files that I need to read are in subfolders. In each subfolder there are four asc files. I only need to access one file in each folder and read the headers and columns below (look at the pictures attached).There are more than 10,000 fies in subfolders that I need to read in. I want to create variables for latitude, longitude,starting-time and the colums CO,z,T (see the attached files). At the end there will be variables such as this.

latitude: 10,000*1

longitude:10,000*1

etc.

z: 10,000*23 (23 is for 23 altitude levels)

T: 10,000*23

CO : 10,000*23

Any help will be greatly appreciated.

[Stephen23]

@Anton Fernando: please upload a sample file. We cannot test code on screenshots.

[Anton Fernando]

See the attached file.

Answer 1

[Stephen23]

This will read the data from one file (attached):

[fid,msg] = fopen('sr36161v4.0.txt','rt');
assert(fid>=3,msg)
% Preamble data:
pfx = struct();
boo = true;
while boo
    str = strtrim(fgetl(fid));
    boo = ~isempty(str);
    if boo
        tmp = strtrim(regexp(str,'\|','split'));
        val = str2double(tmp{2});
        if isnan(val)
            pfx.(tmp{1}) = tmp{2};
        else
            pfx.(tmp{1}) = val;
        end
    end
end
% Header data:
while isempty(str)
    val = ftell(fid);
    str = strtrim(fgetl(fid));
end
str = regexprep(str,{'\s*\(','\)'},{'_',''});
hdr = regexp(str,'\s+','split');
% Column data:
fseek(fid,val,'bof');
fmt = repmat('%f',1,numel(hdr));
tmp = textscan(fid,fmt,'HeaderLines',1);
tmp = [hdr;tmp];
out = struct(tmp{:});
fclose(fid);

You can access the preample data in pfx, e.g.:

>> pfx.name
ans = ace.sr36161
>> pfx.latitude
ans =  18.430

And the column data in out, e.g.:

>> out.z
ans =
     0.50000
     1.50000
     2.50000
     3.50000
     4.50000
     5.50000
     6.50000
     7.50000
     8.50000
     9.50000
     .... lots of lines here
   143.50000
   144.50000
   145.50000
   146.50000
   147.50000
   148.50000
   149.50000

[Stephen23]

Anton Fernando's "Answer" moved here:

Wow. Works like a charm. Thank you very much. :)

[Stephen23]

@Anton Fernando: then please show your thanks by accepting my answer.

You made the mistake of writing your comment in an "Answer" and then accepting it, which does not give credit to the volunteer who actually helped you. Please use comments for commenting.

Answer 2

[KSSV]

A simple googling will give you tons of sites for this querry. Example:

https://in.mathworks.com/matlabcentral/answers/245959-how-to-read-text-files-from-different-sub-folders-in-a-folder

[Anton Fernando]

I actually found multiple similar solutions. I am not a heavy matlab user. Therefore when the coding gets complicated it becomes difficult for me to figure out how to modify a given soultion for my particualr problem. The answer you posted does not explain very well with enough comments how to modify it for a different question. (Maybe it did, But the codes are really complcated). But thank you very much.

[Anton Fernando]

I figured out a way to save all the file names I need. Thanks. Now I only need to read data from individual files.