% function tide_bc_empty(nx, ny, cbdry_used, tide_num) 
%
%
%  Make a dummy tidal bc for cbdry_used {'s', 'n', 'w', 'e'} 
%  based on the size on nx and ny  with zero amplitude and phase  
%
% Input:  nx, first   dimension of MITgcm 
%         ny, second  dimension of MITgcm 
%   tide_num, used to decide the dimension of boundary bc file [length, num of tidal constituent] 
% cddry_used, boundary {'s', 'n', 'w', 'e'} to generate empty tidal bc file
%  
%  
% 
%         tide_num[nc<10], Which tide to include, 
%                          m2  s2  n2  k2  k1  o1  p1  q1  mf  mm   
%                          1   2   3   4   5   6   7   8   9   10 
%
% OB[N,S,E,W][am,ph]File :: Files with boundary conditions,
%                           the letter combinations mean:
%              N/S/E/W   :: northern/southern/eastern/western boundary
%              am/ph     :: tidal amplitude (m/s) / radian 
%
%
%  XC WANG /12/12/2012   
%
%addpath /data17/home/xiao/CAT/Tool/TMD2.03   
function tide_bc_empty(nx, ny, cbdry_used, tide_num) 

% addpath /data17/home/xiao/CAT/Tool/TMD2.03   

%model_file =['Model_CATS2008a_opt'];  
model_file =['Model_CATS2008b_km'];   

% Dimension of Boundary files  
% NX, grid points in horizontal direction
% NH, grid points in vertical direction 
% Use the first records to create tidal BC 
%NX=640; NY=640; NH=70;  month_in = 1;  
NX = nx; NY=ny ; 

% 
rad2deg = 180/pi ; 
deg2rad = pi/180 ;   

% Set the Boundary to add tides  
% AngleCS_bc, AngleSN_bc are the Cos and Sin and angle of U axis of MITgcm 
% from due east 
%ibc = 3 ; 
% ibc = 4 ; 
c_bdry3 = cbdry_used ; 

for ibc =length(c_bdry3) 

c_bdry=c_bdry3{ibc} ; 


% Characters for Model Tidal BC file 
cob=upper(c_bdry) ;
fld={'am','ph'}  ;   


if any(strcmp(cob, {'N','S'})) 
 OBlength = NX ; 
 else 
 OBlength = NY ; 
end 


%  Try for one tides only 
% tide_num = 1:c8 ; 
%tide_num = 5 ; 

amp_all = zeros(OBlength, length(tide_num)) ; 
pha_all = zeros(OBlength, length(tide_num)) ;  



% Write to file 
cfld = fld{1} ; 
fnm=['OB' cob cfld '.seaice_obcs']; 
%fnm=['OB' cob cfld '.seaice_obcs.k1']; 
writebin(fnm, amp_all) ;  


cfld = fld{2} ; 
fnm=['OB' cob cfld '.seaice_obcs']; 
%fnm=['OB' cob cfld '.seaice_obcs.k1']; 
writebin(fnm, pha_all) ;     

end 

return