CDF_VARDELETE
=============

The CDF_VARDELETE procedure deletes a variable from a SINGLE_FILE CDF file. 
Note that the variable’s entries are also deleted, and that the variables that 
numerically follow the deleted variable within the CDF file are automatically 
renumbered. CDF rVariables and zVariables are counted separately within CDF 
files. Attempting to delete a variable from a MULTI_FILE format CDF file will 
result in a warning message.

Examples

cid = CDF_CREATE('DEMOvardelete',/SINGLE_FILE)

 

; Create 3 zVariables and 1 rVariable:

var1_id = CDF_VARCREATE(cid, 'rVAR1', /CDF_FLOAT)

var2_id = CDF_VARCREATE(cid, 'zVAR1', /CDF_INT4, /REC_NOVARY, $

   /ZVARIABLE)

var3_id = CDF_VARCREATE(cid, 'zVAR2', /CDF_CHAR, [2,10], $

   NUMELEM=10, DIM=[5,5])

var4_id = CDF_VARCREATE(cid, 'zVAR3' ,/CDF_REAL8, /ZVARIABLE)

 

; Check the number of variables:

info = CDF_INQUIRE(cid)

HELP, info.nzvars, info.nvars

 

; Delete the first and third zvariables:

CDF_VARDELETE, cid, 'zVAR1', /ZVARIABLE

CDF_VARDELETE, cid, 1, /ZVARIABLE

 

; CAUTION: Remember the variable numbers are zero-based

; and are automatically renumbered.

 

info = CDF_INQUIRE(cid)

HELP, info.nzvars, info.nvars

varinfo = CDF_VARINQ(cid, 0, /ZVARIABLE)

; check on zVAR2

HELP, varinfo, /STRUCTURE

 

CDF_DELETE, cid

IDL Output

<Expression> LONG = 3

<Expression> LONG = 1

 

<Expression> LONG = 1

<Expression> LONG = 1

 

** Structure <400a3b40>, 8 tags, length=48, refs=1:

   IS_ZVAR INT 1

   NAME STRING    'zVAR2'

   DATATYPE STRING    'CDF_CHAR'

   NUMELEM LONG 10

   RECVAR STRING    'VARY'

   DIMVAR BYTE Array(2)

   ALLOCATERECS LONG Array(2)

   DIM LONG Array(1)

Syntax

CDF_VARDELETE, Id, Variable [, /ZVARIABLE]

Arguments

Id

The CDF ID of the file containing the Variable to be deleted, returned from a 
previous call to CDF_OPEN or CDF_CREATE.

Variable

A string containing the name of the variable to be deleted OR the variable 
number to be deleted. Variable numbers are 0-based in IDL. zVariables and 
rVariables are counted separately in CDF files.

Keywords

ZVARIABLE

Set this keyword if the Variable is a zVariable and was passed by number. The 
default is to assume that Variable is an rVariable.

Version History

4.0.1b

Introduced

See Also

CDF_ATTDELETE, CDF_CONTROL, CDF_VARCREATE, CDF_VARINQ

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