How to change the content of file?

Hello,

I I would like to change the content of a .txt file via a for loop, if it is possible.

I would like thw first value to be 10 and the last 250, and I want the content to be changed per 10 (I mean for k=10:10:250).

I am importing the .txt file.

How could I do that?

[Walter Roberson]

Is the number the only thing in the file? If so then just keep writing new files ignoring the current content of the file.

[Ivan Mich]

I would like to do it only with this way. It is important for my code. Yes , the only thing I would like to change is this number

[Walter Roberson]

in your real file, is the number the only thing that is in the file and it occupies the one and only line in the file? Or are there additional lines? if there are additional lines then is it always the same relative position to change or does the number have to be located after varying amounts of text?

[Ivan Mich]

Look , I have file with one line. My code needs the line to be changed via a loop. after every iteration I would like to change the number. I am Importing the file that comes from the first iteration.

[Bjorn Gustavsson]

Would something a simple as:

load Document2.txt -ascii
% do some work
Document2 = Document2 + 10;
% possibly do some more work
save Document2.txt Document2 -ascii

[Walter Roberson]

save -ascii puts in a line of comments

[Bjorn Gustavsson]

@Walter: What version of matlab started with that?

Answer 1

[Walter Roberson]

filename = 'Document2.txt';

while true 
  Val = load(filename) + 10;
  if Val > 250; break; end
  fid = fopen(filename, 'wt') ;
  fprintf(fid, '%g\n', Val) ;
  fclose(fid) ;
end

Not the way that I would implement myself, but for some reason it is important to you to work this way.