function vabs, v

;+
; NAME:
;  vabs
; PURPOSE: (one line)
;  Return the length of a vector
; DESCRIPTION:
;  Return the length of a vector
; CATEGORY:
;  Math
; CALLING SEQUENCE:
;  len = abs(v)
; INPUTS:
;  v - a vector of arbitrary length
; OPTIONAL INPUT PARAMETERS:
;  none
; KEYWORD INPUT PARAMETERS:
;  none
; KEYWORD OUTPUT PARAMETERS:
;  none
; OUTPUTS:
;  sqrt(total(v^2))
; COMMON BLOCKS:
;  None
; SIDE EFFECTS:
; RESTRICTIONS:
;  None
; PROCEDURE:
; MODIFICATION HISTORY:
;  Written 2000, by Leslie Young, SwRI
;  2006 Jan 12 LAY change to double
;-

 len = sqrt(total( double(v)^2.d))
  return, len
;   
end