function [z] = cart2cyl(c,thetai,rhoi,varargin)
% z=cart2cyl(c,xi,yi);
%
% Re-grids model output in cylindrical coords to cartesian.
%  c     is a 2-D or 3-D scalar or z-vector field
%  xi,yi are vectors of the new regular lat-lon grid to interpolate to.
%  z     is the interpolated data with dimensions of size(xi) by size(yi).
%
% e.g.
% >> t=rdmds('Ttave.0000513360');
% >> xi=-179:2:180;yi=-89:2:90;
% >> ti=cyl2cart(t,xi,yi);
%

NN=size(c);
%[theta rho nz]=size(c);
[x y nz]=size(c);
%[RHO,THETA] = meshgrid(1:rho,-pi+2*pi/theta:2*pi/theta:pi);
[Y,X] = meshgrid(-(x-1)/2:(x-1)/2,-(y-1)/2:(y-1)/2);
%[x,y] = pol2cart(THETA,RHO);
[theta,rho] = cart2pol(X,Y);
theta=(theta./(pi*2)+0.5).*size(thetai,2);
%theta=rot90(theta.*180./pi,-1);
%[nx ny nz]=size(c);
%nx=theta;ny=rho;
ntheta=x;nrho=y;

%X=reshape(x,[1 nx*ny]);
%Y=reshape(y,[1 nx*ny]);
THETA=reshape(theta,[1 ntheta*nrho]);
RHO=reshape(rho,[1 ntheta*nrho]);
%del=griddata_preprocess(Y,X,yi,xi',varargin{:});
del=griddata_preprocess(RHO,THETA,rhoi,thetai',varargin{:});

for k=1:nz;
 C=reshape(c(:,:,k),[1 ntheta*nrho]);
z(:,:,k)=griddata(RHO,THETA,C,rhoi,thetai',varargin{:});
%z(:,:,k)=griddata(Y,X,C,yi,xi',varargin{:});
% z(:,:,k)=griddata_fast(del,[C C(il) C(ig)],varargin{:});
end % k

% Split vertical and time dimensions
if size(NN,2)>2
z=reshape(z,[size(z,1) size(z,2) NN(3:end)]);
end