|
NetCDF (Network Common Data Form) is a set of software libraries and self-describing, machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data. The project homepage is hosted by the Unidata program at the University Corporation for Atmospheric Research (UCAR). They are also the chief source of netCDF software, standards development, updates, etc. The format is an open standard. NetCDF Classic and 64-bit Offset Format are an international standard of the Open Geospatial Consortium. The project started in 1989 and is still actively supported by UCAR. Version 3.x (released in 1997) is still widely used across the world and maintained by UCAR (last update 2012). Version 4.0 (released in 2008) allows the use of the HDF5 data file format. Version 4.1 (2010) adds support for C and Fortran client access to specified subsets of remote data via OPeNDAP. Both Version 3 and Version 4 are planned to be updated by UCAR. The format was originally based on the conceptual model of the Common Data Format developed by NASA, but has since diverged and is not compatible with it. ==Format description== The netCDF libraries support 3 different binary formats for netCDF files: * The classic format was used in the first netCDF release, and is still the default format for file creation. * The 64-bit offset format was introduced in version 3.6.0, and it supports larger variable and file sizes. * The netCDF-4/HDF5 format was introduced in version 4.0; it is the HDF5 data format, with some restrictions. All formats are "self-describing". This means that there is a header which describes the layout of the rest of the file, in particular the data arrays, as well as arbitrary file metadata in the form of name/value attributes. The format is platform independent, with issues such as endianness being addressed in the software libraries. The data are stored in a fashion that allows efficient subsetting. Starting with version 4.0, the netCDF API allows the use of the HDF5 data format. NetCDF users can create HDF5 files with benefits not available with the netCDF format, such as much larger files and multiple unlimited dimensions. Full backward compatibility in accessing old netCDF files and using previous versions of the C and Fortran APIs is supported. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「NetCDF」の詳細全文を読む スポンサード リンク
|