CDF_INQUIRE

The CDF_INQUIRE function returns global information about the Common Data Format file. The tags of this structure are described below.

Examples

cdfid = CDF_CREATE('CDFinquire', /HP_ENCODING, /MAC_DECODING)

attr1_id = CDF_ATTCREATE(cdfid, 'GLOBAL_ATT', /GLOBAL_SCOPE)

attr2_id = CDF_ATTCREATE(cdfid,'VARIABLE_ATT', /VARIABLE_SCOPE)

CDF_CONTROL, cdfid, GET_NUMATTRS = num_attrs

PRINT, 'This CDF has ', num_attrs(0), $

   'Global attribute(s) and ', num_attrs(1), $

   'Variable attribute(s).', $

   FORMAT='(A,I2,A,I2,A)'

inquire = CDF_INQUIRE(cdfid)

HELP, inquire, /STRUCT

CDF_DELETE, cdfid ; Delete the CDF file.

This CDF has  1 Global attribute(s) and  1 Variable attribute(s).

** Structure <4003e0c0>, 9 tags, length=48, refs=1:

   NDIMS           LONG                 0

   DECODING        STRING    'MAC_DECODING'

   ENCODING        STRING    'HP_ENCODING'

   MAJORITY        STRING    'ROW_MAJOR'

   MAXREC          LONG                -1

   NVARS           LONG                 0

   NZVARS          LONG                 0

   NATTS           LONG                 2

   DIM             LONG      Array(1)

Result = CDF_INQUIRE(Id)

This information is returned in a structure of the form:

{ NDIMS:0L, DECODING:"", ENCODING:"", MAJORITY:"", MAXREC:0L, $

  NVARS:0L, NZVARS:0L, NATTS:0L, DIM:LONARR(NDIMS) }

The structure returned by this function consists of the following tags:

Tag	Description
NDIMS	The longword integer specifying the number of dimensions in the rVariables in the current CDF.
DECODING	A string describing the decoding type set in the CDF file, such as ‘MAC_DECODING’ or ‘ALPHAVMSD_ENCODING’.
ENCODING	A string describing the type of encoding used in the CDF file, such as ‘NETWORK_ENCODING’ or ‘SUN_ENCODING’.
MAJORITY	A string describing the majority used in the CDF file. The majority will be either row (‘ROW_MAJOR’) or column (‘COL_MAJOR’).
MAXREC	A longword integer specifying the highest record number written in the rVariables in the current CDF. The MAXREC field will contain the value -1 if no rVariables have yet been written to the CDF.
NVARS	A longword integer specifying the number of rVariables (regular variables) in the CDF.
NZVARS	A longword integer specifying the number of zVariables in the CDF.
NATTS	A longword integer specifying the number of attributes in the CDF. Note that the number returned in this field includes both global and variable attributes. You can use the GET_NUMATTR keyword to the CDF_CONTROL routine to determine the number of each.
DIM	A vector where each element contains the corresponding dimension size for the rVariables in the current CDF. For 0-dimensional CDF’s, this argument contains a single element (a zero).

A CDF ID, returned from a previous call to CDF_OPEN or CDF_CREATE.

None

Pre 4.0

Introduced