Matlab read and write file in loop

I have several csv files and want to read this file in a loop, the files are called a1.csv, a2.csv, a3.csv I can read those files like this

csvfiles = dir('*.csv')

for file = csvfiles'
    fprintf(1,'Doing something with %s\n',file.name)
end

Within this loop I have to do some calculation with the data of each file. After this I want to store the output in several files according to the original name like a1_output.txt, a2_output.txt, a3_output.txt. Any help how I can do this?

Answer 1

[Thorsten]

 csvfiles = dir('*.csv')
 filenames = {csvfiles.name}
 for fn = filenames
   fprintf(1,'Doing something with %s\n', char(fn))
   [~, n] = fileparts(char(fn)); 
   outfn = [n '_output.txt']
 end

[Carina]

Thanks a lot