Problem with creating a new .txt file.

Hello

I have a problem with a code. Well, I would like to add to a specific line of a file one more number. The thrid line has this content:

"oficcial".

After using code I would like the third line to have this format:

"oficcial 25".

In order to make it I am using these commands,

sm=regexp(fileread('orders.txt'), '\r?\n', 'split') .';
replaced_lines=[sm(1:2);sm(3)"25"; sm(4:5)]
fid = fopen('new.txt', 'wt');
fprintf(fid, '%s\n', replaced_lines{:});
fclose(fid)

but command window shows me error:

Invalid use of operator.

Could anyone help me?

I am importing two files in order to understand the problem.

Answer 1

[Tommy]

You'll need to get the character vector contained within the 1x1 cell array sm(3) by instead using sm{3}, then horizontally concatenate '25', then place the result back in a cell array so it can be concatenated with sm(1:2) and sm(4:5):

sm=regexp(fileread('orders.txt'), '\r?\n', 'split') .';
replaced_lines=[sm(1:2);{[sm{3} '25']}; sm(4:5)];
fid = fopen('new.txt', 'wt');
fprintf(fid, '%s\n', replaced_lines{:});
fclose(fid);

(edit) The following is simpler and would also work:

sm=regexp(fileread('orders.txt'), '\r?\n', 'split') .';
sm{3} = [sm{3} '25'];
fid = fopen('new.txt', 'wt');
fprintf(fid, '%s\n', sm{:});
fclose(fid);

[Ivan Mich]

Ok, one question.. If I want to use a loop in order to put a spesific value by each iteration How could I write it?

I mean I have a value, M=66. I am writing this command:

replaced_lines=[sm(1:2);{[sm{3} 'M']}; sm(4:5)];

in order to replace the line 3, with the line:

oficcial 66.

But Command window shows me the following error:

Undefined function or variable 'sm'

Could you help me?

[Tommy]

Have you run the line

sm=regexp(fileread('orders.txt'), '\r?\n', 'split') .';

first in order to obtain sm?

Also, if M equals 66, to get your desire output you'll need

replaced_lines=[sm(1:2);{[sm{3} num2str(M)]}; sm(4:5)];

[Ivan Mich]

Unfortunately I have tried the commands you suggested , before I sent you in order not to annoy you again, but it not works..

Could you suggest me something else?

[Tommy]

Can you post all of your code here? I'm not entirely sure what you meant by "I want to use a loop in order to put a spesific value by each iteration" Are you trying to create multiple new text files, one per iteration?

[Ivan Mich]

ok, I have one txt file ( I am importing it as "file1.txt"). I want from this file to take each value, putting it in the point I mentioned and creating a new txt file.

clc
clear

sm=regexp(fileread('orders.txt'), '\r?\n', 'split') .';
M=regexp(fileread('file1.txt'), '\r?\n', 'split') .';

for i=1:size(M,1)
    replaced_lines=[sm(1:2);{[sm{3} num2str(M(i,:)]}; sm(4:5)];
    fid = fopen('new%d.txt', i+1);
    fprintf(fid, '%s\n', replaced_lines{:});
    fclose(fid);
end

an example of one file that comes out from this code is the file new1.txt that I am importing too.

Thank you in advance

[Tommy]

Okay I see. A few comments:

(1) As M is a cell array, just like sm, then M(i) will give you another cell array. To obtain the data within M, you should use M{i}.

(2) I did not realize that your numbers were coming from another file. Your code stores the numbers as character vectors within M, rather than as doubles like I initially assumed, so the call to num2str isn't needed.

(3) In this line:

fid = fopen('new%d.txt', i+1);

you are passing i+1, a double, as the second argument to fopen. If you check the docs, that is not a valid second argument to pass to fopen. It looks like you are trying to format the filename by placing i+1 where the '%d' is located. In that case, you should use sprintf. fopen alone doesn't know anything about formatting.

(4) Per the fopen documentation:

"If you open a file with write or append access and the file is not in the current folder, then fopen creates a file in the current directory."

Here is where we need the second argument to fopen. I believe any permission other than just 'r' (the default) counts as some form of writing or appending.

So, the following should work:

sm=regexp(fileread('orders.txt'), '\r?\n', 'split') .';
M=regexp(fileread('file1.txt'), '\r?\n', 'split') .';

for i=1:size(M,1)
    replaced_lines=[sm(1:2);{[sm{3} M{i}]}; sm(4:5)];
    fid = fopen(sprintf('new%d.txt', i+1), 'w');
    fprintf(fid, '%s\n', replaced_lines{:});
    fclose(fid);
end
    fid = fopen('new%d.txt', i+1);