The primary environment for analysis within the Root for STAR framework is the Maker. Makers are "links" in the analysis chain. They must have one or more of the following parts (implemented as member functions):

• Initialization [Init() member function]: Any set-up steps, or any before-run-only processing must go here.
• Analysis [Make() member function]: This member function implements any processing that should be done on an event-by-event basis.
• Conclusion [Finish() member function]: Wrap up the analysis and/or do any post-event-loop processing.

If you want to make your own Maker, Akio Ogawa has written a detailed diary of his efforts for taking the St_TLA_Maker template and creating a new Maker. I found some new problems of my own when I decided to follow Akio's path. When making your own Maker, you may wish to look here for some of the details you might need to know:

• Constructor: St_xxx_Maker() member function
  • You should not have to do much alteration of the constructor from the template. Some default and intialization values can be set here.

• Initialization: Init() member function
  • Any parameter tables you wish to use for all events should be constructed/pointed in Init(). A new table will require allocation of a St_Table-derived table class (see Using Tables). You are also welcome to use your own new classes for data-handling.
  • Book any diagnostic histograms you wish to provide here.
  • For safety of future compatibility, call the StMaker::Init() member function if you define your own Init() member function too.

• Analysis: Make() member function
  • Any event-specific input tables you use must be re-found for each event in Make(). See Using Tables for getting pointers to existing tables, and StEvent documentation for using StEvent data.
  • Event-specific output tables must be created for each event in Make() and added to the dataset for the Maker. See Using Tables for tips on how to make a new table. New tables must be added to the dataset via a pointer to the dataset as follows:

              m_DataSet->Add(aaa_name);

    Here, m_DataSet is the pointer to the dataset, inherited from the StMaker class for each Maker's dataset, and aaa_name is a pointer to the St_Table-derived table. Or, again, you are welcome to create and use your own classes for output data structures.
  • If you are calling a PAM routine which was originally written for StAF, then you will need to make sure you have all the table pointers you need ready, and be sure to have amongst your includes the one for the wrapper for the specific PAM. This is generally in the form: "domain/St_name_am_Module.h", where name is the PAM name and domain is the name of the domain where the module is located (e.g. global, strange, emc, etc.). Generally, the module needs only to be called with the table pointers in relevant order (unlike StAF, the table header pointers can be omitted). You can find and look at the source code for the PAM wrappers in $STAR/.share/domain.

• Event Clear: Clear() member function
  • A Maker needs its own Clear() member function if it builds constructs outside the dataset which need to be destroyed after each event. Anything in the dataset (tables in particular) should not be deleted.

• Conclusion: Finish() member function
  • If you are doing any processing which only occurs after some number of events n, then you may need to be sure the processing finishes if the total number of events is not an even multiple of n by doing some processing here. (e.g. only updating histograms every 100 events)
  • For safety of future compatibility, call the StMaker::Finish() member function if you define your own Finish() member function too.

• Include file: St_xxx_Maker.h file
  • Any data members which should not be saved with this Maker and its dataset must have "//!" on the same line as the declarartion. This is a particularly valid note for pointers, whose values are meaningless if read in another session. Examples of this can be seen in many Maker header files.
  • Any classes which are referenced in the header (e.g. "TH1F *m_histo;" refers to the TH1F class) must have a class statement before the Maker class statement (in this case, there must be a statement "class TH1F;" earlier in the header file which precedes the "class St_xxx_Maker" statement.
  • You can add the comment "// *MENU*" to the end of a line on which you have a particular member which you woul like to be available from a browser in Root.

• Miscellaneous:
  • Be sure to keep the ClassDef and ClassImp statements in the header and source code files respectively. These are macros which autmoatically insert necessary STAR code into the Makers.
  • Remember that any tables, histograms, TCanvases, TPads, ... any classes defined externally to this Maker ... will require include files to be specified either in the source file or in the header file if they are going to be used in the Maker class definition.
  • Don't be afraid to add new member functions to your maker which make the implementation better or easier to understand. Remember to put them in the header file too. It may be best to keep these functions hidden from public use.