| 1 |
% $Header$ |
% $Header$ |
| 2 |
% $Name$ |
% $Name$ |
| 3 |
|
|
| 4 |
%% * Introduction |
\section{NetCDF I/O Integration} |
|
%% o what it does, citations (refs go into mitgcm_manual.bib, |
|
|
%% preferably in alphabetic order) |
|
|
%% o Equations |
|
|
%% * Key subroutines and parameters |
|
|
%% * Reference material (auto generated from Protex and structured comments) |
|
|
%% o automatically inserted at \section{Reference} |
|
|
|
|
|
|
|
|
\section{MNC: the MITgcm NetCDF Package} |
|
| 5 |
\label{sec:pkg:mnc} |
\label{sec:pkg:mnc} |
| 6 |
|
|
| 7 |
\subsection{Introduction} |
The \texttt{mnc} package is a set of convenience routines written to |
| 8 |
|
expedite the process of creating, appending, and reading NetCDF files. |
| 9 |
|
NetCDF is an increasingly popular self-describing file format |
| 10 |
|
\cite{rew:97} intended primarily for scientific data sets. An |
| 11 |
|
extensive collection of NetCDF reference papers, user guides, |
| 12 |
|
software, FAQs, and other information can be obtained from UCAR's web |
| 13 |
|
site at: |
| 14 |
|
\begin{rawhtml} <A href="http://www.unidata.ucar.edu/packages/netcdf/"> \end{rawhtml} |
| 15 |
|
\begin{verbatim} |
| 16 |
|
http://www.unidata.ucar.edu/packages/netcdf/ |
| 17 |
|
\end{verbatim} |
| 18 |
|
\begin{rawhtml} </A> \end{rawhtml} |
| 19 |
|
|
|
The MNC package is a set of convenience routines written to expedite |
|
|
the process of creating, appending, and reading NetCDF files. NetCDF |
|
|
is a self-describing file format \cite{rew:97} intended primarily for |
|
|
scientific data. NetCDF reference papers, user guides, FAQs, and other |
|
|
information can be obtained from UCAR's web site at: |
|
| 20 |
|
|
| 21 |
\begin{itemize} |
\subsection{Introduction} |
|
\item http://www.unidata.ucar.edu/packages/netcdf/ |
|
|
\end{itemize} |
|
| 22 |
|
|
| 23 |
|
The \texttt{mnc} package is a two-level convenience library (or |
| 24 |
|
``wrapper'') for most of the NetCDF Fortran API. Its purpose is to |
| 25 |
|
streamline the user interface to NetCDF by maintaining internal |
| 26 |
|
relations (``look-up tables'') keyed with strings (or ``names'') and |
| 27 |
|
entities such as NetCDF files, variables, and attributes. |
| 28 |
|
|
| 29 |
|
The two levels of the \texttt{mnc} package are: |
| 30 |
|
\begin{description} |
| 31 |
|
|
| 32 |
|
\item[Upper level] \ |
| 33 |
|
|
| 34 |
|
The upper level contains information about two kinds of |
| 35 |
|
associations: |
| 36 |
|
\begin{description} |
| 37 |
|
\item[Grid type] is lookup table indexed with a grid type name. |
| 38 |
|
Each grid type name is associated with a number of dimensions, the |
| 39 |
|
dimension sizes (one of which may be unlimited), and starting and |
| 40 |
|
ending index arrays. The intent is to store all the necessary |
| 41 |
|
size and shape information for the Fortran arrays containing |
| 42 |
|
MITgcm--style ``tile'' variables (that is, a central region |
| 43 |
|
surrounded by a variably-sized ``halo'' or exchange region as |
| 44 |
|
shown in Figures \ref{fig:communication_primitives} and |
| 45 |
|
\ref{fig:tiling-strategy}). |
| 46 |
|
|
| 47 |
|
\item[Variable type] is a lookup table indexed by a variable type |
| 48 |
|
name. For each name, the table contains a reference to a grid |
| 49 |
|
type for the variable and the names and values of various |
| 50 |
|
attributes. |
| 51 |
|
\end{description} |
| 52 |
|
|
| 53 |
|
Within the upper level, these associations are not permanently tied |
| 54 |
|
to any particular NetCDF file. This allows the information to be |
| 55 |
|
re-used over multiple file reads and writes. |
| 56 |
|
|
| 57 |
|
\item[Lower level] \ |
| 58 |
|
|
| 59 |
|
In the lower (or internal) level, associations are stored for NetCDF |
| 60 |
|
files and many of the entities that they contain including |
| 61 |
|
dimensions, variables, and global attributes. All associations are |
| 62 |
|
on a per-file basis. Thus, each entity is tied to a unique NetCDF |
| 63 |
|
file and will be created or destroyed when files are, respectively, |
| 64 |
|
opened or closed. |
| 65 |
|
|
| 66 |
|
\end{description} |
| 67 |
|
|
| 68 |
|
|
| 69 |
|
\subsection{Key subroutines, parameters and files} |
| 70 |
|
|
| 71 |
\subsection{Key Routines} |
All of the variables used to implement the lookup tables are described |
| 72 |
|
in \filelink{pkg/mnc/mnc\_common.h}{pkg/mnc/mnc_common}. |
| 73 |
|
|
| 74 |
|
|
| 75 |
|
|
| 76 |
\subsection{References} |
\subsection{Package Reference} |
Parent Directory
| 
Revision Log
| 
Revision Graph
| 
Patch