Report 34:  EzGet: A Library of Fortran Subroutines to Facilitate Data Retrieval

Taylor, Karl E.
April 1996, 70 pp. 

---

The software described in this document is designed to facilitate retrieval of modeled and observed climate data stored in popular formats including DRS, netCDF, GrADS, and, if a control file is supplied, GRIB. You can specify how the data should be structured and whether it should undergo a grid transformation before you receive it, even when you know little about the structure of the stored data (i.e., its dimension order, grid, and domain).

The software is referred to here as EzGet (pronounced "easy-get") and it comprises a set of subroutines that can be linked to any FORTRAN program. EzGet reads files through the cdunif interface which is available from the Program for Climate Model Diagnosis and Intercomparison (PCMDI), but use of EzGet does not require familiarity with cdunif. The main advantages of using this software instead of the lower level cdunif library include:

• Substantial error trapping capabilities and detailed error messages
• Versatile capability of conveniently selecting data from specified regions (e.g., oceans, North America, all land areas north of 45 degrees latitude, etc.)
• Ability to map data to a new grid at the time it is retrieved by EzGet
• Automatic creation of "weights" for use in subsequent averaging or masking of data
• Increased control in specifying the domain, grid and structure of the retrieved data.
  
Taken together these capabilities will simplify the process of writing programs for accessing data stored in different formats and structures, including all the observed data sets and the model output from various model intercomparison projects (AMIP, PMIP, CMIP, etc.) archived at PCMDI.

EzGet software and the latest version of this document are available through the PCMDI web site: http://www-pcmdi.llnl.gov/ktaylor/ezget/ezget.html
For a pdf version of this document go to (pdf file)

UCRL-MI-123395

---