% $Id$

% Earth System Modeling Framework
% Copyright (c) 2002-2025, University Corporation for Atmospheric Research, 
% Massachusetts Institute of Technology, Geophysical Fluid Dynamics 
% Laboratory, University of Michigan, National Centers for Environmental 
% Prediction, Los Alamos National Laboratory, Argonne National Laboratory, 
% NASA Goddard Space Flight Center.
% Licensed under the University of Illinois-NCSA License.

\section{Background}

Output data from programs usually consists of a combination of numerical data,
stored in formats such as NetCDF, visual data, and diagnostics.  The log 
utility is intended to organize diagnostic output.  Many programs use simple 
Fortran {\tt write} statements, and the output resulting from such statements
in the multiprocessor environment is unpredictable and inconsistent at best.  
The utility tries to make this behavior predictable across computing 
environments.  It also attempts to organize the diagnostic output so that 
searches and filters may be easily constructed.

\subsection{Location}

This utility is part of the infrastructure.  This is an extremely low level 
object and will be used by most of the other objects in the project.  It will 
thus not depend on the other objects in the library save perhaps the machine 
model.

\subsection{Scope}

The log will be for diagnostic output.  The bandwidth is assumed to be moderate
to small, i.e. it will not be used to output large streams of numerical model 
output data.  



