Introduction



Period04 is a computer program especially dedicated to the statistical analysis of large astronomical time series containing gaps. As its predecessor, Period98, 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.

Fundamentally, the program is composed of 3 modules:



Some tools or functions are only accessible when the program operates in the so called 'Expert mode'.

Period04 is project oriented and saves all data (time string data, Fourier spectra, frequencies and the log) in one central project file. The project file itself is completely platform independent. This allows the user to switch between various operating systems. As the program also stores the current program settings along with the data, it is easy to resume work on a project.

Backwards compatibility


Period04 is based on Period98 by Martin Sperl. Period98 project files (.p98) can be read by Period04 without problems. The default extension for Period04 project files is .p04 though.

Obtaining Period04


Period04 is freely available and has been compiled for Linux, Windows and MacOSX. The program can be downloaded from the Period04 website:
http://www.univie.ac.at/tops/Period04/.
The installers will guide you through the installation process.

Requirements


Period04 is a Java/C++ hybrid program. Therefore, to run the program a Java Runtime Environment (JRE) has to be installed. The JRE is already preinstalled on every Mac OS X System. Windows and Linux users will have to check if there is a JRE is on their system. To do that simply open a shell or a command prompt and type
java -version
If the command is not found no Java is installed. In this case you have to download it from http://java.sun.com (it's free). If the java command exists, please check the version number. The Period04 binary works with all versions from 1.6.0.