c
c WaveSol.f	provides solutions to the Deep Water
c		surface gravity wave problem with
c		initial conditions as derived on 
c		page 32-38 of class notes
c
c Andreas Muenchow, University of Delaware
c March-14, 2018
c
	integer ix,it,nx,nt
	real*8 g,A,x,t,arg,eta,dx,dt,eta0
c
	pi = 4.*atan2(1.,1.)
	g = 9.81
	A = sqrt(pi*g)/2./pi
	dx = 0.2
	dt = 0.05
	nx = 300
	nt = 300
c
c Recall solution is valid only 
c	far from generation location x=0 and time t=0
c
	do 1 it=1,nt
	do 2 ix=1,nx
	   x = 20.+ix*dx
	   t = 20.+it*dt
		arg = (g*t*t/4./x)+pi/4.
c Wave
		eta = A * t/(x*sqrt(x)) *  dcos(arg)
c Evenlope
		eta0 = A * t/(x*sqrt(x))
c Data file
	   write(16,101)x,t,eta,ix,it,eta0,-eta0
c
2	continue
1	continue
101	format(2f10.3,f10.5,2i4,2f10.5)
	stop
	end