Re: Help me to extract the part of Text file to another format

[Ben Abbott]

> On Mar 12, 2016, at 7:22 AM, mjayiitk2013 <address@hidden> wrote:
> 
> Hi all,
> 
> I have a text file  40%ROL~1.TXT
> <http://octave.1599824.n4.nabble.com/file/n4675435/40%25ROL%7E1.TXT>   who
> has pattern of this kind
> 
> info info info
> info X X X
> Info
> offset 0
> 1 344
> 2 43432
> 4 34234
> 3 4323
> X-ray
> Info
> Info
> offset 0
> 1 3441
> 2 43431
> 4 34231
> 3 4321
> X-ray
> ....
> ....
> I want to extract the second column between "offset 0" to "X-Ray" in a row
> then another piece in another row
> like
> 344 43432 34234 4323
> 3441 43431 34231 4321
> 
> I have similar files a lot so i want to change all in this manner
> Please guide me to make a script for it

I process a lot of text data at work. Below is an approach I like. It places 
each range of data in the structure array, dat.

txt = fileread ("220.txt");
txt = strsplit (txt, "\n");
ok = @(c) cellfun (@(x)!isempty(x), c, "uniformoutput", true);
txt(!ok(txt)) = [];

header_begin = find (ok (regexpi (txt, "^X-Ray.*")));
header_end = find (ok (regexpi (txt, "^Offset.*")));

dat = struct ();
for n = numel(header_begin):-1:1
  for m = header_begin(n):header_end(n)
    str = strsplit (txt{m}, '\s', ...
                    "delimitertype", "regularexpression", ...
                    "collapsedelimiters", true);
    dat(n).(str{1}) = str2double (str{2});
    if (isnan (dat(n).(str{1})))
      dat(n).(str{1}) = str{2};
    end
  end
  num = round ((dat(n).Stop - dat(n).Start) / dat(n).Step);
  m = header_end(n) + (1:num);
  dat(n).data = vertcat (cellfun (@str2num, txt(m), "uniformoutput", false){:});
end

To collect all the data in a single 2D array ...

all_data = vertcat (cellfun (@(x)x(:,2).', {dat.data}, “uniformoutput", 
false){:})

Ben