function xyz2radec, xyz

;+
; NAME:
;  xyz2radec
; PURPOSE: (one line)
;  Convert from xyz to ra, dec
; DESCRIPTION:
;  Convert from xyz to ra, dec
; CATEGORY:
;  Astronomy
; CALLING SEQUENCE:
;  radec = xyz2radec(xyz)
; INPUTS:
;  xyz - vector of [x,y,z]
; OPTIONAL INPUT PARAMETERS:
;  none
; KEYWORD INPUT PARAMETERS:
;  none
; KEYWORD OUTPUT PARAMETERS:
;  none
; OUTPUTS:
;  radec - vector of [ra, dec] in radians
; COMMON BLOCKS:
;  None
; SIDE EFFECTS:
; RESTRICTIONS:
;  None
; PROCEDURE:
; MODIFICATION HISTORY:
;  Written 2000, by Leslie Young, SwRI
;  2006 Jan 12 LAY change to doubles.
;-

  xyzn=normv(xyz)
  x=xyzn(0)
  y=xyzn(1)
  z=xyzn(2)
  return, [(atan(y,x)+2.d*!dpi) mod (2.d*!dpi), asin(z)]
end