How can i save the output of a matrix to a text file within loop

Hello Sir, i am having a question regarding dlmwrite ... is it possible to use dlmwrite within a loop to save results in text file each time with new file name.

what i am doing is taking several thousands inputs , for which i used looping method, within loop, a file is taken as input and then apply some functions and bla bla stuff of DSP applied over it, and output comes which is stored in a variable called as "D" ... that output is in the form of "m x m" matrix (Square matrix) and i want to save that result in a txt file. and the loop goes on to the next input... can you tell me how to do so

to do it on a single file, without using loop, i am doing this in by this manner

img=imread(image.png);
%function here some long calculation which leads to results in a matrix called D
D=function_results;
dlmwrite("results.txt",D);

now that works fine for a single file without loop. Now can you give some guidelines regarding saving within loop, Like

- loop starts, (I've done this)
- read the file, (I've done this)
- apply the function, (I've done this)
- store results in variable "D" (I've done this)
- that result saves in text file whose name is the same name of the input file but extension be text ( not able to solve this riddle)
- display the result (I've done this)
- go to next file  (I've done this)

Thanking in regards.

P.S. I've tried save and fprintf, but i am not able to achieve the desired results.

[Hassaan Mustafa]

Sorry, i forget to mention, my all results are in the form of binary and i have to keep the results in binary for further stages