README roottools
12/5/2003  D. Lawrence


This directory contains tools useful for integrating ROOT
into the PrimEx analysis software. It was created, in particular,
to provide an easy, consistent way for programs to serve up histograms
in an online environment so that remote root sessions could access
them while they are being filled.

To make histograms available:
--------------------------------

1. Include roottools.h header to your main program and hist_book.cc

#include "roottools.h"


2. Set the port number for the TCP/IP connection in main(). This number
is specific to the program since all must be unique. Several subsystems
already have values reserved. These can be found in roottools.C. Here's
a list:
9090 tac
9091 hycal
9092 ps
9093 veto
9094 tagger

ROOT_SERVER_PORT = 9090;


3. Register the root server init and event procedures with PEvent_Loop.

event_loop.RegisterINITProc(InitRootServer);
event_loop.RegisterEVNTProc(RootServer);


To access histograms remotely:
--------------------------------

1. Start up ROOT and load the roottools.C file

>root
root [0] .L roottools.C

2. If you are running root on a different machine than the server is
running on, set the host of the server location (skip this step
if running on the same machine)

root [1] sethost("clon00")

3. List the histograms available for a specfic system

root [2] cd("tac")
root [3] ls()

4. Retrieve a histogram and draw it

root [4] Draw("tac_tdc")

5. The most recently retrieved histogram (via Draw()) will stay in
memory until a newer version is retrieved with the same name.