Name

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  Class MGHncFile

Purpose

---

  This class encapsulates a netCDF file for READ and WRITE
  access. It exposes methods for manipulating dimensions, variables
  and attributes. C.f. the MGHncReadFile class, which allows
  read-only access.

Category

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  Scientific Data Formats.

Properties

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  ATT_NAMES (Get)
    A list of global attributes taken from the netCDF file. If the
    file has no attributes, then this property returns an empty string.
    See N_ATTS.
  FILE_NAME (Init, Get)
    The name of the netCDF file wrapped by the MGHncFile object.
  N_ATTS (Get)
    The number of global attributes in the netCDF file.
###########################################################################
  Copyright (c) 2013 NIWA:
  http://www.niwa.co.nz/
  Licensed under the MIT open source license:
  http://www.opensource.org/licenses/mit-license.php
###########################################################################

Modification History

---

  Mark Hadfield, 1997-04:
    Written as NcFile
  Mark Hadfield, 1999-05:
    Renamed to MGHncFile.
  Mark Hadfield, 2000-05:
    Minor changes to property & keyword names.
  Mark Hadfield, 2000-11:
    Retrieve method rewritten to use the MGH_STRUCT_BUILD function.
  Mark Hadfield, 2001-06:
    Updated for IDL 5.5.
  Mark Hadfield, 2001-11:
    Major overhaul of interface along with MGHncReadFile and
    MGHncSequence.
  Mark Hadfield, 2003-01:
    The VarGet method has been enhanced in the same ways as
    MGHncReadFile's VarGet method: a zero value in the COUNT vector
    means get all data and a negative value in the OFFSET vector
    specifies an offset relative to the end of the dataset.
  Mark Hadfield, 2003-05:
    Discovered & fixed a long-standing bug in the VarGet method:
    in the code activated by AUTOSCALE=1, the WHERE function was
    returning a variable "count" which trampled on the keyword variable
    of the same name. It becomes a problem when the keyword variable
    is passed back to the caller and used in a second call to VarGet.
    It's amazing I never hit this one before.
  Mark Hadfield, 2003-05:
    Code now upgraded for IDL 6.0, including its new features for
    logical data. Added the new (experimental) NONULL keyword to
    all calls to NCDF_ATTPUT.
  Mark Hadfield, 2006-11:
    Fixed bug: HasAtt didn't work on variable attributes. How did this
    stay undiscovered for so long?!
  Mark Hadfield, 2007-06:
    Fixed bug reported by Metthew Savoie: UNLIMITED property incorrect
    when the first dimension in the file is unlimited.
  Mark Hadfield, 2009-02:
    Corrected minor error in VarGet.
  Mark Hadfield, 2010-10:
    - The code in the VarInfo method to dermine the FILL_VALUE
      property has been replaced with the corresponding code from the
      MGHncReadFile object. It can cope with the NCDF_VARINQ function
      returning a datatype of either 'INT' or 'SHORT' for a 2-byte
      integer.
    - The VarAdd method can now accept either INT or SHORT
      keywords. Both cause the new variable to contain 2-byte
      integer data.
  Mark Hadfield, 2013-10:
    - Added NETCDF3_64BIT and NETCDF4_FORMAT keywords, to be used when creating files.
    - Removed NETCDF3_64BIT again: not available before version 8.2.1!
  Mark Hadfield, 2014-03:
    - An important fix to the AttPut method when writing IDL strings: the CHAR
      keyword is now passed explicitly to NCDF_ATTPUT to ensure that strings
      get written as the netCDF CHAR type rather than the netCDF STRING type. See
      http://www.unidata.ucar.edu/mailing_lists/archives/netcdfgroup/2014/msg00100.html