% converts U (rho), V (theta) and W in polar coords into 
% proper u,v, and w in cartesian coords, plus into theta and
% rho vector components in a more physical annulus layout

% load data
U=rdmds('U');
V=rdmds('V');
W=rdmds('W');
T=rdmds('T');
% set null-space areas to NaN (makes interpolation happier)
U(find(U==0))=NaN;
V(find(V==0))=NaN;
W(find(W==0))=NaN;
T(find(T==0))=NaN;

% this determines resolution of interpolated fields
% 0.5 is perhaps a bit fine, but it looks pretty
step=0.5;
% good for quiver plots
% step=1;

% convert theta/rho vector fields to u/v
[u v]=cyl2cartuv(U,V,-30:step:30,-30:step:30);

% convert w (effectively a scalar)
 w=cyl2cart(W,-30:step:30,-30:step:30);
% Tc=cyl2cart(T,-30:step:30,-30:step:30);

% interpolate theta and rho into annulus
 azim=cyl2cart(U,-30:step:30,-30:step:30);
 radial=cyl2cart(V,-30:step:30,-30:step:30);