Introduction

Histo-Scope is a tool to select and display histograms, Ntuples, and scalar values from a program as data is being created or analyzed. Using Histo-Scope, physicists can interactively "browse" through the large quantities of statistical data that their analysis and data acquisition programs gather as they run. It is intended to complement existing physics applications, and provides new interactive methods for viewing data with immediate access to data while a program is running.

Histo-Scope requires an X-based workstation (DEC/ULTRIX, DEC/OSF-1, SGI, Sun, or IBM/Risc) or an X Terminal or X-based workstation that can connect to one of these hosts. In addition, if HBOOK histograms or Ntuples are to be viewed, the HBOOK software is required on the host that creates the data.

Histo-Scope has two parts. One part is a library of routines which can be inserted in the physics analysis or data acquisition code without significantly changing its behavior. No restrictions are imposed upon the user analysis process except that it must periodically call an update routine. It does not need to run on a workstation, and is not linked with any graphical user interface code. These user library routines are described in Part III of this guide.

The other part of Histo-Scope is the "scope" program. Running as a separate, concurrent process (and possibly running on a diferent machine), the scope requests and displays data from the data creation process. The scope is easy to use. It responds to mouse and keyboard input and provides the interactive graphing and plotting that enable users to view their data quickly and effectively. Using the Histo-Scope program is described in Part I of this guide. Users familiar with graphical user interfaces will probably want to skim through this part of the manual, especially the section User Interface Overview.

Histo-Scope is intended to be used in an online environment as well as in offline applications. In contrast to other existing histogramming packages, Histo-Scope was designed to have somewhat limited capabilities for exhaustive analysis of histograms or Ntuples. Instead, it is a small, highly interactive tool, written exclusively for workstations or X-terminals supporting Motif and X-Windows graphics. It emphasizes graphics representation, graphics speed, and maximum exploitation of windowing and mouse interaction. For example, while Histo-Scope does not provide curve fitting, it does provide a number of animation techniques such as dynamic re-binning of Ntuple histograms and the ability to interactively rotate two dimensional histogram plots.