Extract data between specific indicators from txt file

I have a demo1.txt file that looks something like this

 R1 0.222 0.444 0.555
    0.777 0.999
NR8 0.001 0.002 0.003
    0.004 0.008
NR1 0.004 0.009 0.008
    0.006 0.009

I would like to only extract the numbers in the R1 section (in this case, search for the exact match as the string "R1", grab all numbers after "R1" up until NaN), then create an excel spreadsheet named "demo1" and have the following entries in a column:

R1
0.222
0.444
0.555
0.777
0.999

Any hint will be appreciated! Thank you very much!

[Mathieu NOE]

soryy

I'm tired

this is now the good one

data_str = 'R1';

%% main loop 
out_total = [];
nn = (strfind(ll,data_str));
out = str2double(split(ll(nn(1):nn(2))));
out(isnan(out)) = [];

% write to excel a table 
t = array2table(out,'VariableNames',{data_str});
writetable(t,'output3.xlsx');

[chlor thanks]

My bad! This code only works on my previous txt file example.

But my actual txt file is more complicated like shown in the updated txt file.

And I only needed

R1
0.222
0.444
0.555
0.777
0.999

[chlor thanks]

Never mind I figured it out by myself, thanks for the inspiration and stepping in to help anyways!

clc;
clear;
Str   = fileread('data.txt');
TStr  = split(Str)
TStr_R1 = find(strcmp(TStr, 'R1'))
R1_end = str2double(TStr(TStr_R1:end))
R1_nan = find(isnan(R1_end));
R1 = R1_end((R1_nan(1)+1):(R1_nan(2)-1))

Answer 1

[Mathieu NOE]

hello

this is one solution - hope it helps !

tested with the attached txt file

 = readlines('data.txt');

data_str = 'R1';


%% main loop 
out_total = [];
mm = (strfind(ll,data_str));

for ci = 1:numel(mm)
    if cell2mat(mm(ci)) > 0
        out = str2double(split(ll(ci)));
        out(isnan(out)) = [];
        out_total = [out_total; out(:)];
    end
end

% write to excel a table 
t = array2table(out_total,'VariableNames',{data_str});
writetable(t,'output.xlsx');

[chlor thanks]

Thank you!

But this did not work even after I try modifying it. All it was able to write is R1 itself:

clc;
clear;
content = fileread( 'data.txt' ) ;
R1 = 'R1';
%% main loop 
out_total = [];
mm = (strfind(content,R1));
for ci = 1:numel(mm)
    if mm(ci) > 0
        out = str2double(split(content(ci)));
        out(isnan(out)) = [];
        out_total = [out_total; out(:)];
    end
end
% write to excel a table 
t = array2table(out_total,'VariableNames',{R1});
writetable(t,'output.xlsx');

[Mathieu NOE]

maybe I didn't paste correctly my code

see attached

[chlor thanks]

For example, readlines doesnt exist in my matlab

[Mathieu NOE]

ok , ths should work for you

ll = fileread('data.txt');
data_str = 'R1';

%% main loop 
out_total = [];
mm = (strfind(ll,data_str));
rr = strfind(ll,'    ');

for ci = 1:numel(mm)
        ind1 = mm(ci);
        ind2 = rr(ci);
        out = str2double(split(ll(ind1:ind2)));
        out(isnan(out)) = [];
        out_total = [out_total; out(:)];
    
end

% write to excel a table 
t = array2table(out_total,'VariableNames',{data_str});
writetable(t,'output2.xlsx');

[chlor thanks]

Thank you very much for the updated code! So far looks like it extracted

  R1 
 
  0.222 
 
  0.444 
 
  0.555 
 
  0.004 
 
  0.009 
 
  0.008 
  

but I need

R1
0.222
0.444
0.555
0.777
0.999