Write a function called digit_counter that takes the name of a text file as input and returns the number of digits (i.e., any of the characters, 0-to-9) that the file contains. If there is a problem opening the file, the function returns -1.

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Vaibhav Dwivedi
Vaibhav Dwivedi on 7 Oct 2017
Commented: Walter Roberson on 7 Feb 2019
My code:
function[c]=digit_counter(filename)
fid=fopen(filename,'rt');
if fid<0
error('error opening file %s', filename);
end
A = char(fread(fid,inf)).';
c=length(A);
fclose(fid);
end
I am getting the error:
Not enough input arguments.
Error in digit_counter (line 2)
fid=fopen(filename,'rt');
Can somebody pls help me out here.

Answers (5)


Image Analyst
Image Analyst on 7 Oct 2017
You're not even building the histogram. See if you can finish this:
counts = zeros(1, 10); % Histogram.
fileChars = fileread('test1.m');
for k = 1 : length(fileChars)
theInteger = str2double(fileChars(k));
if ~isreal(theInteger)
% isreal is used because a letter i evaluates as 1 + 1*i (complex)
continue;
end
if ~isnan(theInteger)
% Increment histogram by 1
index = theInteger + 1; % Convert from 0-based to 1-based indexing.
counts(index) = counts(index) + 1;
end
end
counts

Srishti Saha
Srishti Saha on 11 Mar 2018
This should definitely work:
%function: digit_counter in a file; takes file name as argument
function dc = digit_counter(filename)
dc=-1;
fid= fopen(filename,'r');
if fid>=0
dc= nnz(isstrprop(fileread(filename),'digit'));
fclose(fid);
end
end

Ranil Fernando
Ranil Fernando on 3 Jun 2018
I'm getting a strange error to this problem.
Problem 1 (digit_counter):
Feedback: Your function performed correctly for argument(s) 'digit_counter.m'
Feedback: Your function performed correctly for argument(s) 'day_counter.m'
Feedback: Your function performed correctly for argument(s) 'smallest_multiple.m'
Feedback: Your function performed correctly for argument(s) 'maxproduct.m'
Feedback: Your function performed correctly for argument(s) 'number2letters.m'
Feedback: Your function performed correctly for argument(s) 'circular_primes.m'
Feedback: Your function performed correctly for argument(s) 'cyclotron.m'
Feedback: Your function performed correctly for argument(s) 'huge_add.m'
Feedback: Your program made an error for argument(s) 'Non-existent file. This should generate an error'
Your solution is _not_ correct.
and my code is;
function digi_num = digit_counter(filename)
digi_num = 0;
str_len = [];
digi_ch = {'0','1','2','3','4','5','6','7','8','9'};
fid = fopen(filename,'rt');
if fid < 0
digi_num = -1;
end
str_line = fgets(fid); %read file as string
while ischar(str_line)
str_len = length(str_line);
for ii = 1:str_len
for jj = 1:10
if str_line(ii)==digi_ch{jj}
digi_num = digi_num + 1;
end
end
end
str_line = fgets(fid);
end

RAMAKANT SHAKYA
RAMAKANT SHAKYA on 7 Feb 2019
function d=digit_counter(filename)
fid=fopen(filename,'r');
if fid<0
d=-1;
else
A = char(fread(fid,inf))';% reading all data from the text file
k=isstrprop(A,'digit'); %determines if elements of input text are of the specified category, numbers
d= nnz(k);% Number of nonzero matrix elements.
fclose(fid);
end
end

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