netcdf/

mg_nc_getdata.pro

file i/o, netcdf, sdf

includes main-level program

Routine for extracting datasets, slices of datasets, or attributes from an netCDF file with simple notation.

Examples

An example file is provided with the IDL distribution:

  IDL> f = filepath('hdf5_test.h5', subdir=['examples', 'data'])

A full dataset can be easily extracted:

  IDL> fullResult = mg_h5_getdata(f, '/arrays/3D int array')

Slices can also be pulled out:

  IDL> bounds = [[3, 3, 1], [5, 49, 2], [0, 49, 3]]
  IDL> res1 = mg_h5_getdata(f, '/arrays/3D int array', bounds=bounds)
  IDL> help, res1
  RESULT1         LONG      = Array[1, 23, 17]

Verify that the slice is the same as the slice pulled out of the fullResult:

  IDL> same = array_equal(fullResult[3, 5:*:2, 0:49:3], res1)
  IDL> print, same ? 'equal' : 'error'
  equal

Normal IDL array indexing notation can be used as well:

  IDL> bounds = '3, 5:*:2, 0:49:3'
  IDL> res2 = mg_h5_getdata(f, '/arrays/3D int array', bounds=bounds)
  IDL> print, array_equal(res1, res2) ? 'equal' : 'error'
  equal

The variable location and bounds can be combined to slice a variable:

  IDL> res3 = mg_h5_getdata(f, '/arrays/3D int array[3, 5:*:2, 0:49:3]')
  IDL> print, array_equal(res1, res3) ? 'equal' : 'error'
  equal

Attributes can be accessed as well:

  IDL> print, mg_h5_getdata(f, '/images/Eskimo.CLASS')
  IMAGE

This example is available as a main-level program included in this file:

  IDL> .run mg_nc_getdata

Author information

Author: Michael Galloy

Other file information

Todo:

better error messages when items not found access for global attributes

top source mg_nc_getdata

result = mg_nc_getdata(filename, variable [, bounds=lonarr(3, ndims) or string] [, error=long])

Pulls out a section of a netCDF variable.

Return value

data array

Parameters

filename in required type=string

filename of the netCDF file

variable in required type=string

variable name (with path if inside a group)

Keywords

bounds in optional type=lonarr(3, ndims) or string: gives start value, end value, and stride for each dimension of the variable
error out optional type=long: error value

File attributes

Modification date:	Wed Sep 28 16:19:14 2011
Lines:	417
Docformat:	rst rst

Personal library of Michael Galloy
Contact me if you have enhancement requests or bug fixes.

idllib

Personal IDL library for M. Galloy