function [UU,WW]=wing_2(x0,y0,XX,ZZ)
[x,y,u,v]=vtheta();
xx=x+x0*ones(size(x));
yy=y+y0*ones(size(y));
UU=interp2(xx,yy,u,XX,ZZ,'linear',0.0);
WW=interp2(xx,yy,v,XX,ZZ,'linear',0.0);
return