how to identify values in a text file and replace them based on an existing array

Hello,

I have a text file, let's call it abc.txt, such as that I am writing below. I would like to replace the values that are after '=' of each line that starts in ARF

Example:

ARF1=0.4
ARF2=0.6
ARF3=0.7
ARF4=0.8
ARF5=0.7
ARF6=0.6
ARF7=0.4
asd
asd
gh
wer
asd
qwe
asd

with the values of an existing array:

B=[3;5;4;6;5;3;8]

so the resultant text file would be:

ARF1=3
ARF2=5
ARF3=4
ARF4=6
ARF5=5
ARF6=3
ARF7=8
asd
asd
gh
wer
asd
qwe
asd

How could I do it?

I am using MATLAB R2018b.

Best regards,

Hugo

[Walter Roberson]

fileread(), do some careful regexprep(), write out to a new file.

Answer 1

[Ameer Hamza]

This is one of the way

B=[3;5;4;6;5;3;8];

fid = fopen('data.txt');
data1 = textscan(fid, 'ARF%f=%f');
data2 = textscan(fid, '%s');
fclose(fid);

data1_new = compose('ARF%d=%.0f', data1{1}, B);
data_new = [data1_new; data2{1}];

fid = fopen('data_new.txt', 'w');
fprintf(fid, '%s\n', data_new{:});
fclose(fid);

data.txt is attached.

Answer 2

[Mathieu NOE]

hello

this is a way to do it

T =  readtable('data.txt');
% T =
% 
%   14×2 table
% 
%       Var1      Var2
%     ________    ____
% 
%     {'ARF1'}    0.4 
%     {'ARF2'}    0.6 
%     {'ARF3'}    0.7 
%     {'ARF4'}    0.8 
%     {'ARF5'}    0.7 
%     {'ARF6'}    0.6 
%     {'ARF7'}    0.4 
%     {'asd' }    NaN 
%     {'asd' }    NaN 
%     {'gh'  }    NaN 
%     {'wer' }    NaN 
%     {'asd' }    NaN 
%     {'qwe' }    NaN 
%     {'asd' }    NaN 

% conversion table to cell array
TC = table2cell(T);

TC_out = TC; % initialization (out put table = input table)

% new data
B=[3;5;4;6;5;3;8];


[m,n] = size(TC);
p = 0;

for ci = 1:m
    if findstr(TC{ci},'ARF')
        p = p+1;
        TC_out{p,2} = B(p);
    end
end
    
% save TC_out to table 
writecell(TC_out,'data_out.txt');