;
; rotate the dataset in azimuth by the requested angle
; positive rotation az rotates CCW looking down from positive z
;
; ARGS:
; XYZ[3,N]: DOUBLE   vector to rotate
; theta   : double   angle in degrees to rotate (+ i cw)
;
function rotatedata,xyz,theta
;
;   note that the rotvec routine rotates CCW by default
;
	return,(rotvec(xyz,theta,axis=3,/usedouble))
end