Open a text file and count the number of digits

Hi, I need a function that takes as an input the name of another file (either .txt or .m), opens it and counts the number of digits present.

This is what I have so far but it always returns either -1(file could not be opened) or 0.

function num = digit_counter(filename)
fid=fopen(filename,'rt');
if fid<0
    num=-1;
else
num=0;
for k=0:9
    n=count(filename,'1');
    num=num+n;
end
end

Thanks in advance!

[Stephen23]

Your code opens a file but never closes it: this is not a good idea, you should close all files that you open.

What do you expect this

count(filename,'1')

to do? Does your assignment require you to count the '1' characters in the filename? If you need to count the digits in the file data, then you need to import the file data somehow. Start by reading the MATLAB documentation:

https://www.mathworks.com/help/matlab/standard-file-formats.html

https://www.mathworks.com/help/matlab/low-level-file-i-o.html

[Ricardo Higinio Picon Alvaro]

Yeah sorry that should be a k, so the for loop goes round checking for each of the numbers individually!

[dpb]

What's the content of the file?

Depending on what it is, there are some much more clever "Matlab'y" ways to do this.

Answer 1

[dpb]

function [num,n] = digit_counter(filename)
% Returns total number and optional distribution of integers 0 thru 9
% in text file filename

    fid=fopen(filename,'r');    % NB: include error handling for real
    f=fread(fid,'char');        % read as character array full file
    n=histc(f,'0':'9');         % find, bin the integers in the file
    num=sum(n);                 % get the total number
    fid=fclose(fid);
  end