Create multiple copies of a .txt file according to N x 1 array

I have an N by 1 array that contains random integer values, say A = [101, 790, 477, ... , 999]. I also have a text file, say MyFile.txt, that contains rows of alphanumeric data. I wish to replace an integer value that appears on the 2nd row in MyFile.txt with an integer value from array A and then save this with a unique file name. I wish to repeat this for each element in the array A. This process should result in N text files as follows: MyFile_101.txt, MyFile_790.txt, MyFile_477.txt , ... , MyFile_999.txt.

Is there an efficient way to automate the above using a matlab script?

[Dyuman Joshi]

Can you attach the text file - 'MyFile.txt' ? Use the paperclip button to attach.

[Matthew Worker]

Hi Dyuman, thanks for the reply. Please find attached. Note: it is the value 786 on line 2 that I wish to change each time.

Answer 1

[Dyuman Joshi]

The data in the text file is heterogeneous and stored non-uniformly. This approach should work for that -

y = readlines('MyFile.txt')

y = 19×1 string array
    "  0"
    "   786"
    "      101"
    "           1"
    "           1"
    "           3"
    "           0"
    " H"
    " A"
    " J"
    " K"
    "h7lA"
    "K"
    "9"
    "11"
    "M"
    "AK"
    "PP"
    ""

%String to be replaced
str = strip(y(2))

str = "786"

%Let A be the array of values that need to be replace
A = [101, 790, 477, 999];

for k=1:numel(A)
    z=y;
    %Replacing the values
    z(2) = regexprep(z(2),str,string(A(k)));    
    %Writing to a text file
    %These files will be stored in the current directory
    %You can change the path according to where you want to store them
    writelines(z,sprintf('MyFile_%d.txt', A(k)));
end

[Matthew Worker]

That's perfect, works a charm, thank you!

[Dyuman Joshi]

You are welcome!

[Dyuman Joshi]

In that case, fprintf to the rescue -

y = readlines('MyFile.txt');
%String to be replaced
str = strip(y(2));
%Let A be the array of values that need to be replace
A = [101, 790, 477, 999];

for k=1:numel(A)
    z=y;
    %Replacing the values
    z(2) = regexprep(z(2),str,string(A(k)));    
    %Creating file to store
    fid = fopen(sprintf('MyFile_%d.txt', A(k)),'wt');
    %Printing the data
    fprintf(fid,'%s\n',z);
    %Closing the file
    fclose(fid);
end

%Checking the contents
type MyFile_790.txt

  0
   790
      101
           1
           1
           3
           0
 H
 A
 J
 K
h7lA
K
9
11
M
AK
PP