function [u_new,v_new] = rotate_winds (u,v,angle)

% Transforms u and v to a new frame of reference.
% Inputs:   u - eastward component of wind speed
%           v - northward component of wind speed
%           angle - angle to rotate by in degrees (positive=clockwise,
%           negative = anticlockwise)
% Outputs:  u_new - new u vector
%           v_new - new v vector
% 
% CEB Jan 2012

u_new = u.*cosd(angle) - v.*sind(angle);
v_new = u.*sind(angle) + v.*cosd(angle);