WHY DO TEACHERS USE CDF FILES MANUALS
WHY DO TEACHERS USE CDF FILES SOFTWARE
WHY DO TEACHERS USE CDF FILES CODE

V3.0 is backward compatible with CDF V2.7, V2.6, and V2.5, but not vice versa. CDF was originally written in FORTRAN and only ran in VAX/VMS environments.ĬDF V3.0 was released on February 10, 2005. Translators among various data formats, including CDF are available at ĬDF was designed and developed in 1985 by the National Space Science Data Center (NSSDC) at NASA/GSFC. In 2002, the CDF office developed an XML-based markup language called CDF Markup Language (CDFML) to describe CDF data and metadata. The structure of CDF allows one to define an unlimited number of variables completely independent (loosely coupled) of one another and disparate in nature, a group of variables that illustrate a strong dependency (tightly coupled) on one another or both simultaneously.Ĭompared to HDF format, CDF permitted cross-linking data from different instruments and spacecraft in ISTP with one development effort (according to ).įile type signifiers and format identifiers The CDF structure is based on variable definitions (name, data type, number of dimensions, sizes, etc.) where a collection of data elements is defined in terms of a variable. APIs in Fortran and C are available for all versions, in Java for version 2.7 and up.ĭata documentation (quality, provenance, etc.)Ĭapabilities for embedding user documentation for the dataset as a whole or for particular elements through a data dictionary can support documentation of precision, provenance, etc.ĬDF is designed to support multi-dimensional data. Hence the specification focuses on an API rather than on organization of data in files.

WHY DO TEACHERS USE CDF FILES SOFTWARE

The basic component of CDF is a software programming interface that is a device-independent view of the CDF data model. Support for software interfaces (APIs, etc.) Guidelines for the Space Physics community are found at Additional metadata appropriate for any particular dataset can be stored as attribute entries as part of the application data within the CDF. CDF has been adopted by the International Solar-Terrestrial Physics (ISTP) project as well as the Central Data Handling Facilities (CDHF) as their format of choice for storing and distributing key parameter data.'ĬDF is supported by commercial and open source data analysis/visualization software such as IDL, MATLAB, and IBM's Data Explorer (XP).ĬDF control information acts as an embedded data dictionary. From CDF FAQ: 'The CDF software package is used by hundreds of government agencies, universities, and private and commercial organizations as well as independent researchers on both national and international levels. Maintained by the Space Physics Data Facility (SPDF) at NASA/Goddard Space Flight Center.

WHY DO TEACHERS USE CDF FILES MANUALS

Documentation includes CDF User's Guide and complete list of APIs and their descriptions in reference manuals for the supported programming languages.

WHY DO TEACHERS USE CDF FILES CODE

Source code for the CDF software package is also freely available.Īvailable from. Specifications of the format and the APIs in Java, C, and Fortran are freely available. The Library of Congress Recommended Format Specifications for Datasets lists the CDF file format as an acceptable format.įully documented. Has several versions not documented separately here. Generally used for middle- and final-state archiving. CDF files created on any given platform can be transported to any other platform to which CDF is ported and used with any CDF tools or layered applications.ĬDF Version 2.7 and up contain support for Java Application Program Interfaces (APIs), in addition to the C and Fortran APIs of earlier versions.

The application developer is insulated from the actual physical file format for reasons of conceptual simplicity, device independence, and future expandability.

This self-describing property allows CDF to be a generic, data-independent format that can store data from a wide variety of disciplines. In addition to the actual data being stored, CDF also stores user-supplied descriptions of the data, known as metadata. Draft status: Partial (low priority for LC)ĬDF is a conceptual data abstraction for storing, manipulating, and accessing multidimensional data sets.

Why do teachers use cdf files