% clc
% clear all

u = 0.5
v = 0.5
x = 0.0
y = 5.0
pi = 4*atan(1) % pi declaration
freq = -2.*pi/(24.*3600.)
f = 2*freq                % Coriolis parameter
dt = 24*3600/200      % time step
% parameters for semi-implicit scheme
alpha = f*dt
beta = 0.25*alpha*alpha
ntot = 200; %total number of interation steps
mode = 2   % choose between mode 1 and mode 2
% temp=[] 
for i=1:ntot
    time=i*dt
   un = (u*(1-beta)+alpha*v)/(1+beta);
   vn = (v*(1-beta)-alpha*u)/(1+beta); 
   xn = x + dt*un/1000;
   yn = y + dt*vn/1000;
   

u = un
v = vn
x = xn
p(i)=x
p=p'
y = yn;
r(i)=y
r=r'
q(i)=time
q=q'
end