;+
; NAME:
;	BadValue
; PURPOSE:
;	Provide the Not A Number value for any data type
; CATEGORY:
;	sat/idl/toolbox
; CALLING SEQUENCE:
	FUNCTION BadValue, X
; INPUTS:
;	X			variable of any type
; OUTPUTS:
;	Result		scalar; type: as implied by 'size' vector
;					NaN value
; INCLUDE:
	@compile_opt.pro	; On error, return to caller
; CALLS:
;	IsType
; PROCEDURE:
;	For integers the number zero is returned.
;	For floating point the appropriate value from !values is returned.
; MODIFICATION HISTORY:
;	MAR-2000, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;-

CASE IsType(X) OF
IsType(/byte_x): NaN = 0B
IsType(/short ): NaN = 0
IsType(/long  ): NaN = 0L
IsType(/float ): NaN = !values.f_nan
IsType(/double): NaN = !values.d_nan
ELSE: NaN = 0
ENDCASE

RETURN, NaN  &  END