If you have any difficulty to find it just go here: Period04
“Period04 is a computer program especially dedicated to the statistical analysis of large astronomical time series containing gaps. The program offers tools to extract the individual frequencies from the multiperiodic content of time series and provides a flexible interface to perform multiple-frequency fits.”
For Ubuntu linux users download Period04 package with Java, which is a .sh (shell file).
Run the file either at a terminal like:
$ sh filename.sh
or
$ bash filename.sh
either make it an executable and run it as:
$ chmod +x filename.sh
$ ./filename.sh
During installation the preferred folder path and the initial setup is at /user/bin/ which is local only (this means that you have to go the this folder and run the program like ./period04). If you want to make it global (to have access to the program by simply typing period04 at the terminal) you just have to delete the file from /user/bin/ and make a link (or a copy) to the program at the (root) /bin folder.