MITgcm_contrib/tides/tide_rot.m

% function [utide_am1 utide_ph1 vtide_am1 vtide_ph1] = tide_rot(utide_am0,utide_ph0,vtide_am0,vtide_ph0,angleCS, angleSN) 
%
% Rotate tidal current parameter from NS and EW to a new coordinate defined by angleCS and angleSN  
%
% Input:  utide_am0, utide_ph0(in deg) 
%         vtide_am0, vtide_ph0(in deg) 
%         AngleCS  angleSN:  cos(alpha), sin(alpha);
%           alpha is the angle between new coordinate (utide_am1, vtide_am1) and due east 
%
% Output:  utide_am1, utide_ph1(in deg)  
%          vtide_am1, vtide_ph1(in deg);  
%
% Both input and output are assumed (1 L) array 
%
% XC WANG /07/12/2012 
%  
function [utide_am1 utide_ph1 vtide_am1 vtide_ph1] = tide_rot(utide_am0,utide_ph0,vtide_am0,vtide_ph0,angleCS,angleSN) 

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

% Convert deg to radian 
utide_ph0 = utide_ph0*deg2rad ; 
vtide_ph0 = vtide_ph0*deg2rad ;  

u1_p1 = utide_am0.*angleCS.*cos(utide_ph0) + vtide_am0.*angleSN.*cos(vtide_ph0) ; 
u1_p2 = utide_am0.*angleCS.*sin(utide_ph0) + vtide_am0.*angleSN.*sin(vtide_ph0) ;  

utide_am1 = sqrt(u1_p1.*u1_p1 + u1_p2.*u1_p2) ;   
sin1 = u1_p2 ./ utide_am1 ; 
cos1 = u1_p1 ./ utide_am1 ; 
utide_ph1 = atan2(sin1, cos1) ; 
utide_ph1 = utide_ph1*rad2deg ; 
 
v1_p1 = -utide_am0.*angleSN.*cos(utide_ph0) + vtide_am0.*angleCS.*cos(vtide_ph0) ; 
v1_p2 = -utide_am0.*angleSN.*sin(utide_ph0) + vtide_am0.*angleCS.*sin(vtide_ph0) ;   
vtide_am1 = sqrt(v1_p1 .* v1_p1 + v1_p2.*v1_p2) ; 
sin1 = v1_p2 ./ vtide_am1 ; 
cos1 = v1_p1 ./ vtide_am1 ; 
vtide_ph1 = atan2(sin1, cos1) ; 
vtide_ph1 = vtide_ph1*rad2deg ;  

return 
end 
1	dimitri	1.1	% function [utide_am1 utide_ph1 vtide_am1 vtide_ph1] = tide_rot(utide_am0,utide_ph0,vtide_am0,vtide_ph0,angleCS, angleSN)
2			%
3			% Rotate tidal current parameter from NS and EW to a new coordinate defined by angleCS and angleSN
4			%
5			% Input: utide_am0, utide_ph0(in deg)
6			% vtide_am0, vtide_ph0(in deg)
7			% AngleCS angleSN: cos(alpha), sin(alpha);
8			% alpha is the angle between new coordinate (utide_am1, vtide_am1) and due east
9			%
10			% Output: utide_am1, utide_ph1(in deg)
11			% vtide_am1, vtide_ph1(in deg);
12			%
13			% Both input and output are assumed (1 L) array
14			%
15			% XC WANG /07/12/2012
16			%
17			function [utide_am1 utide_ph1 vtide_am1 vtide_ph1] = tide_rot(utide_am0,utide_ph0,vtide_am0,vtide_ph0,angleCS,angleSN)
18
19			rad2deg = 180/pi ;
20			deg2rad = pi/180 ;
21
22			% Convert deg to radian
23			utide_ph0 = utide_ph0*deg2rad ;
24			vtide_ph0 = vtide_ph0*deg2rad ;
25
26			u1_p1 = utide_am0.angleCS.cos(utide_ph0) + vtide_am0.angleSN.cos(vtide_ph0) ;
27			u1_p2 = utide_am0.angleCS.sin(utide_ph0) + vtide_am0.angleSN.sin(vtide_ph0) ;
28
29			utide_am1 = sqrt(u1_p1.u1_p1 + u1_p2.u1_p2) ;
30			sin1 = u1_p2 ./ utide_am1 ;
31			cos1 = u1_p1 ./ utide_am1 ;
32			utide_ph1 = atan2(sin1, cos1) ;
33			utide_ph1 = utide_ph1*rad2deg ;
34
35			v1_p1 = -utide_am0.angleSN.cos(utide_ph0) + vtide_am0.angleCS.cos(vtide_ph0) ;
36			v1_p2 = -utide_am0.angleSN.sin(utide_ph0) + vtide_am0.angleCS.sin(vtide_ph0) ;
37			vtide_am1 = sqrt(v1_p1 .* v1_p1 + v1_p2.*v1_p2) ;
38			sin1 = v1_p2 ./ vtide_am1 ;
39			cos1 = v1_p1 ./ vtide_am1 ;
40			vtide_ph1 = atan2(sin1, cos1) ;
41			vtide_ph1 = vtide_ph1*rad2deg ;
42
43			return
44			end