Create a file which stores on each line a letter, a space, and a real number. For example, it might look like this:

Ch9Ex21.m

% use textscan to read in from a file in the

% format letter number and sum the numbers

fid = fopen('letnum.dat');

if fid == -1

 disp('File open not successful')

else

 %Read in data from file

 C = textscan(fid,'%c %f');

 total = sum(C{2}); %Sum the numbers in the file

 fprintf('The sum of the numbers is %.2f\n',total)

 %Error-check file close

 closeresult = fclose(fid);

 if closeresult == 0

 disp('File close successful')

 else

 disp('File close not successful')

 end

end