% Program to read and plot QuikSCAT data

file=' ';

lat=double(ncread(file,...
lon=double(
U=double(
theta=double(

% Troque o flag=-9999 por nan
  
u=U.*cosd(theta);
v=U.*sind(theta);

figure(1)

quiver(lon,lat,u,v,.3,'k')                    
axis('equal','tight')

% Calcule dx
[lixo,dy]=gradient(lat);
dy=dy*111195;

[dx,lixo]=gradient(lon);
dx=
  
[dudx,dudy]=gradient(u);
dudx=dudx./dx;
dudy=dudy./dy;

% Crie indices gud para recortar parte do mapa 


lat=lat(gud);
lon=lon(gud);
u=u(gud);
v=v(gud);

% Calcule o rotacional do vento

rot=