I have output (stored in variable "x") that I want saved into a simple text file. If I use the command: fprintf('%d\n',x); it prints the data in a nice column. This is what I want. Then to save it to a file I try this: fileID = fopen('x.txt'); fprintf('%d\n',x); fclose(fileID); however Matlab does not like this. When I searched the help file, it gave a similar example, so what am I doing wrong here? Thanks in advance!