The CDF_VARINQ function returns a structure containing information about the specified variable in a Common Data Format file.
Examples
See the example for CDF_VARGET.
Syntax
Result = CDF_VARINQ( Id, Variable [, /ZVARIABLE] )
Return Value
The returned structure has the form:
{ IS_ZVAR:0, NAME:"", DATATYPE:"", NUMELEM:0L, $
RECVAR:"", DIMVAR:BYTARR(...) [, DIM:LONARR(...)]}
Note: The DIM field is included in the structure only if IS_ZVAR is one.
Explanation of the Structure Tags
The following table provides structure tag information.
|
Tag |
Description |
|
IS_ZVAR
|
This field will contain a 1 if the variable is a zVariable or a 0 if it is an rVariable.
|
|
NAME
|
The name of the variable.
|
|
DATATYPE
|
A string describing the data type of the variable. The string has the form ‘CDF_XXX’ where XXX is FLOAT, DOUBLE, EPOCH, UCHAR, etc.
|
|
NUMELEM
|
The number of elements of the data type at each variable value. This is always 1 except in the case of string type variables (CDF_CHAR, CDF_UCHAR).
|
|
RECVAR
|
A string describing the record variance of the variable. This is either the string ‘VARY’ or ‘NOVARY’.
|
|
DIMVAR
|
An array of bytes. The value of each element is zero if there is no variance with that dimension and one if there is variance. For zero-dimensional CDFs, DIMVAR will have one element whose value is zero.
|
|
DIM
|
An array of longs. The value of each element corresponds to the dimension of the variable. This field is only included in the structure if the variable is a zVariable.
|
Arguments
Id
The CDF ID, returned from a previous call to CDF_OPEN or CDF_CREATE.
Variable
A string containing the name or an integer containing the index of the variable being inquired.
Keywords
ZVARIABLE
If Variable is a variable ID (as opposed to a variable name) and the variable is a zVariable, set this flag to indicate that the variable ID is a zVariable ID. The default is to assume that Variable is an rVariable ID.
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