;+
; NAME:
;	CarringtonNr
; PURPOSE:
;	Get Carrington rotation number for given time (Yr,Doy)
; CALLING SEQUENCE:
	FUNCTION CarringtonNr, T, lng=lng, degrees=degrees
; INPUTS:
;	T		array; type: standard time structure
;				time
; OPTIONAL INPUTS:
;	/degrees	if set then the heliographic longitude returned
;				in keyword 'lng' is in degrees (default: radians)
; OUTPUTS:
;	CarringtonNr	array; type: integer
;				Carrington rotation number
; OPTIONAL OUTPUTS:
;	lng=lng		array; type: float
;				Carrington (heliographic) longitude in
;				radians or degrees (depending on setting of
;				keyword 'degrees')
; INCLUDE:
	@compile_opt.pro		; On error, return to caller
; CALLS:
;	ToRadians, Carrington
; PROCEDURE:
;	See CarringtonT0 for more details.
; MODIFICATION HISTORY:
;	NOV-1994, Paul Hick (UCSD)
;	SEP-1999, Paul Hick (UCSD/CASS)
;		simplified procedure; argument is now a time structure
;	DEC-2000, Paul Hick (UCSD/CASS)
;		added output keyword 'lng'
;	JAN-2004, Paul Hick (UCSD/CASS; pphick@ucsd.edu)
;		Rewrite using new version of Carrington
;-
n_c = Carrington(T, /get_rotation, fraction=lng)
lng = (2*!dpi)*(1.0d0-lng)/ToRadians(degrees=degrees)

RETURN, n_c  &  END