function ROMS2SWAN_GRID(varargin);
% ROMS2SWAN_GRID - Convert ROMS curvilinear grid to SWAN grid
% roms2swan_grd( 'roms_grd.nc' )
%   or
% roms2swan_grd( x_rho, y_rho, h, mask_rho )
%
%Function to convert a ROMS netCDF depth grid into a SWAN ASCII depth grid,
%and create the SWAN curvilinear coordinates grid.
%If the input is the name of a netCDF file (string), the function calls the variables
%x_rho, y_rho, h, and mask_rho from the file; if the input is four variables, it assumes
%that these are the variables x_rho, y_rho, h, and mask_rho in that order.
%Files output to the ASCII filenames defined in the SWAN input file - bathymetry
%goes to roms_bathy.bot, grid goes to grid_coord.grd.

%Soupy Alexander, 6/11/02
%csherwood@usgs.gov 5/09/05

% These parameters are hard-wired right now
idla = 4; % SWAN layout parameter
hfn = 'roms_bathy.bot'; % bathy file for input to SWAN
gfn = 'grid_coord.grd'; % coordinates file for input to SWAN
ugfn = 'ugrid_coord.grd'; % coordinates for u points for SWAN
vgfn = 'vgrid_coord.grd'; % coordinates for v points for SWAN
exc_val = 9999; % exception value for masking in SWAN

if nargin == 1;
    ncid = netcdf(varargin{1});
%    x_rho = ncid{'lon_rho'}(:);
%    y_rho = ncid{'lat_rho'}(:);
    x_rho = ncid{'x_rho'}(:,:);
    y_rho = ncid{'y_rho'}(:,:);
    x_u = ncid{'x_u'}(:,:);
    y_u = ncid{'y_u'}(:,:);
    x_v = ncid{'x_v'}(:,:);
    y_v = ncid{'y_v'}(:,:);
    h = ncid{'h'}(:);
    mask_rho = ncid{'mask_rho'}(:);
    mask_u = ncid{'mask_u'}(:);
    mask_v = ncid{'mask_v'}(:);
elseif nargin == 4;
    x_rho = varargin{1};
    y_rho = varargin{2};
    h = varargin{3};
    mask_rho = varargin{4};
else
    error('Improper number of inputs:  input netCDF file or four variables.');
end
clear ncid varargin

%Replace the land positions with the flag for land (defined in the SWAN
%input file)
land_values = find(mask_rho == 0);
h(land_values) = exc_val;

%TEST TEST
x_rho = x_rho-x_rho(1,1);
y_rho = y_rho-y_rho(1,1);

%Print depths to the bathy file
[m,n] = size(h);
[mu,nu]= size(x_u);
[mv,nv]= size(x_v);

fid = fopen(hfn,'w');
for index = 1:m;
    for index2 = 1:n;
%        fprintf(fid,'   ');
        fprintf(fid,' %8.2f\n',h(index,index2));
    end
%    fprintf(fid,'\n');
end
%fprintf(fid,'%12.6e\n',h');
%fprintf(fid,'%g\n',h');
fclose(fid);

%Print the rho grid coordinates to the grid file
fid2 = fopen(gfn,'w');
for index = 1:m;
     for index2 = 1:n;
%         fprintf(fid2,'   ');
         fprintf(fid2,'%12.6e\n',x_rho(index,index2));
     end
%     fprintf(fid,'\n');
end
for index = 1:m;
    for index2 = 1:n;
%         fprintf(fid2,'   ');
         fprintf(fid2,'%12.6e\n',y_rho(index,index2));
    end
%     fprintf(fid,'\n');
end
%fprintf(fid2,'%g\n',x_rho');
%fprintf(fid2,'%g\n',y_rho');
%fprintf(fid2,'%12.6e\n',x_rho');
%fprintf(fid2,'%12.6e\n',y_rho');
fclose(fid2);

%Print the u grid coordinates to the grid file
fid3 = fopen(ugfn,'w');
for index = 1:mu;
     for index2 = 1:nu;
         fprintf(fid3,'%12.6e\n',x_u(index,index2));
     end
end
for index = 1:mu;
    for index2 = 1:nu;
         fprintf(fid3,'%12.6e\n',y_u(index,index2));
    end
end
fclose(fid3);

%Print the u grid coordinates to the grid file
fid4 = fopen(vgfn,'w');
for index = 1:mv;
     for index2 = 1:nv;
         fprintf(fid4,'%12.6e\n',x_v(index,index2));
     end
end
for index = 1:mv;
    for index2 = 1:nv;
         fprintf(fid4,'%12.6e\n',y_v(index,index2));
    end
end
fclose(fid4);

fprintf(1,'grid_coord.grd and roms_bathy.bot created by roms2swan_grid.m\n');
fprintf(1,'also created ugrid_coord.grd and v_grid_cooord.grd\n');
fprintf(1,'Suggested SWAN input commands:\n')
fprintf(1,'CGRID CURV %d %d CIRCLE 35 .05 .4 20\n',n-1,m-1)
fprintf(1,'READ COORD 1.0 ''%s'' %d 0 0 FREE\n',gfn,idla);
if(any(land_values)),
    fprintf(1,'INP BOT CURV 0 0 %d %d EXCEPTION %g\n',n-1,m-1,exc_val)
else
    fprintf(1,'INP BOT CURV 0 0 %d %d\n',n-1,m-1)
end
fprintf(1,'READINP BOTTOM 1.0 ''%s'' %d\n\n',hfn,idla)
fprintf(1,'INP VX CURV 0 0 %d %d\n',nu-1,mu-1);
fprintf(1,'INP VY CURV 0 0 %d %d\n',nv-1,mv-1);