How can i load .txt files from folder with a loop?

Hello guys, i have a question. I have a folder with .txt files. How can i load the .txt files from folder with a loop?

For example the folder constists of 5 txt files i.e O1.txt, O2.txt , O3.txt, O4.txt, O5.txt, i want a code to take my function each time one txt file, giving me my result and after take automatically the second .txt file and so on.

And something else, when i have a .txt file with 7543 entries, how can i round the entries to 7000, also i want to do this in random number of entries and each time to rounding the entries in the previous thousand.

Thanks a lot,

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

nrow = size(YourData,1);
newsize = floor(nrow/1000)*1000;
NewData = YourData(1:newsize,:);

[Andreas Parlani]

Thanks a lot!!