# coyote: NCDF_BROWSER

- coyote/FileIO
- [Source code]

NAME

      NCDF_BROWSER

PURPOSE

      This program is designed to make it easier to browse and read the
      data and metadata in netCDF and HDF files. The user can browse files,
      and read the data and metadata into main-level IDL variables. New netCDF
      and HDF files can be opened at any time. The user interacts with the
      program via a browser window (GUI). This program is a wrapper for the
      NCDF_DATA object (ncdf_data__define.pro), which must also be downloaded.
      Note that only HDF files with scientific datasets (SD) can be read currently.
      There is no support for VDATA objects or other objects sometimes found in HDF
      files. Also note that when variables are returned from HDF files, they are returned
      in a calibrated form, if calibration information about the variable is present in the
      file. Calibration information is presented as an extra variable attribute in the
      browser.
         calibratedData = calData.cal * (uncalibratedData - calData.offset)

AUTHOR

      FANNING SOFTWARE CONSULTING
      David Fanning, Ph.D.
      1645 Sheely Drive
      Fort Collins, CO 80526 USA
      Phone: 970-221-0438
      E-mail: david@idlcoyote.com
      Coyote's Guide to IDL Programming: http://www.idlcoyote.com

CATEGORY

      File I/O

CALLING SEQUENCE

      IDL> NCDF_Browser, filename

Arguments

      filename: The name of a netCDF and HDF file to open and browse.

KEYWORD PARAMETERS

      EXTENSION: In general, netCDF and HDF files use *.nc, *.ncf, *.ncdf and *.hdf file extensions to
                 identify themselves as netCDF and HDF files. Some users have their own file extensions.
                 You can use this keyword to identify the file extension you wish to use. If
                 set here, it will be used as the file filter in place of the normal file
                 extensions in DIALOG_PICKFILE.
                     obj = ('NCDF_DATA', file, EXTENSION='*.bin')
      NO_NEW_FILE: If this keyword is set, then the button that allows a new file to be open
                 on the browser is not created.
      NO_READ_ON_PARSE: Normally, when a file is opened it is parsed for information.
                 One piece of information is the minimum and maximum values of the variables.
                 This requires actually reading the variables. This can slow things down
                 considerably is the variable is large. Setting this keyword will suppress
                 the reading of the variables during the parsing of the data file, with the
                 result that no minimum or maximum values will be reported.
      TITLE:     Set this keyword to a string that is on the title bar of the browser.
      XOFFSET:   Set this keyword to the X offset in pixels of the top-left corner of the browser.
      YOFFSET:   Set this keyword to the Y offset in pixels of the top-left corner of the browser.

NOTES

      This program is only a (useful) front-end for a more flexible
      object program of class NCDF_DATA. In this front end, the NCDF_DATA
      object is created and then destroyed when the GUI is destroyed.
      The NCDF_DATA object can be used to read netCDF data in a non-interactive
      way, if you prefer not to use a GUI to interact with the data file.

MODIFICATION HISTORY

      Written by:  David W. Fanning, 03 Feb 2008. Used ideas from many
          people, including Chris Torrence, Ken Bowman, Liam Gumely,
          Andrew Slater, and Paul van Delst.
      Added Extension keyword. DWF. 04 Feb 2008.
      Added error handling and protection for NCDF variables that have a dimension of length zero. 22 April 2009. DWF.
      Added NO_READ_ON_PARSE keyword. 22 April 2009. DWF.
      Now convert NCDF CHAR type variables to strings on output. 22 April 2009. DWF
      Made the default value of NO_READ_ON_PARSE set to 1. 25 June 2009. DWF.
      Added NO_NEW_FILE keyword to suppress the Open File button. 3 February 2010. DWF.
      Added TITLE, XOFFSET, and YOFFSET keywords. 5 February 2010. DWF.
      Fixed a problem with memory leakage when the input file cannot be read. 1 May 2010. DWF.