;+
; NAME:
;	windangle
;
; PURPOSE:
;	Calculate the windangle (and optionally the windspeed) from given
;	values of u and v
;	
; CATEGORY:
;	FUNCTION
;
; CALLING SEQUENCE:
;	windangle,u,v,windspeed=windspeed
;
; EXAMPLE:
;	windangle(u,v)
;
; INPUTS: 
;	u	flt or fltarr: the east(ward) component of the wind vector
;	v	flt or fltarr: the north(ward) component of the wind vector
;
; OPTIONAL INPUT PARAMETERS:
;
; KEYWORD INPUT PARAMETERS:
;
; OUTPUTS
;	windspeed	(flt or fltarr): the windspeed
;
; COMMON BLOCKS:
;
; SIDE EFFECTS: 
;
; RESTRICTIONS:
;	
; PROCEDURE:
;	
; MODIFICATION HISTORY:
;	first implementation Sep 9, 1997 by Dominik Brunner
;-

FUNCTION windangle,u,v,windspeed=windspeed

; check for input

IF (n_elements(u) NE n_elements(v)) OR (n_elements(u) EQ 0) THEN BEGIN
   print,'Error in windangle() calculation'
   return,-1
ENDIF

r2d=180./!pi

windspeed=sqrt(u^2+v^2)
wangle=90.-atan(-v,-u)*r2d

return,wangle

end