function PARAMS_init(Nt)
%
% Sets up initial conditions for PARAMS
%

global PARAMS TRU

rand('state',0); randn('state',0) % make sure output is the same every time
disp('random generators reset')

% mesh size
m    = 100; % grid points 
Xsize= 1; 
% generate mesh
x  = (0:m-1)'*Xsize/(m-1);
z  = sin(3*x);    % terrain height
dx = Xsize/(m-1); % increment in x

% set initial values
S0  = ones(m,1); 
gap = round(0.45*m):round(0.50*m); 
S0(gap)=0; % initial fuel

Ti  = 250;
Ti  = 300;
Ta  = Ti*0.8 ; % ambient atmosphere temperature
T0  = ones(m,1)*Ta; % initial temperature
fire_x = round(0.25*m):round(0.28*m); % initial fire
T0(fire_x) = Ti*2;
dt = 0.005;   % time step
time = 1.2;   % duration 
c1   = 1e-3;    % diffusion
c1   = 1e-2;
c4   = 1800; % specific heat of fuel
c2   = 3; % cooling
delta2 = 250; % randomness in equation
delta2 = 100;
cs = 0.3;     % randomness in fuel supply, between 0 and 1
Ps = 50;      % spotting density
Ps = 100;
Ds = 0.05;    % spotting distance
Ds = 0.1;
Ws = 0.5;     % spotting caried by wind
cslope = 0.005;
windx  = 0.1*(0.1*ones(m,1)+0.05*rand(m,1));

% effect of wind and slope
vx = windx(:)+cslope*[0;(0.5/dx)*(z(3:m)-z(1:m-2));0];  
T = T0(:);
S = S0(:);
S = S+(cs*2)*(S.*(rand(size(S))-0.5));
Smax = max(S);


%  OUTPUT
TRU = [T;S];
PARAMS.u0 = [T;S];
PARAMS.mesh.m  = m;
PARAMS.mesh.x  = x;
PARAMS.mesh.dx = dx;
PARAMS.mesh.z  = z;
PARAMS.dt   = dt;
PARAMS.Smax = Smax;
PARAMS.Ti   = Ti;
PARAMS.time = time;
PARAMS.delta2 = delta2;
PARAMS.c1 = c1;
PARAMS.c2 = c2;
PARAMS.c3 = 1;
PARAMS.Ta = Ta;
PARAMS.c4 = c4;
PARAMS.Ps = Ps;
PARAMS.Ds = Ds;
PARAMS.Ws = Ws;
PARAMS.mesh.vx   = vx;
PARAMS.time   = 0;
PARAMS.stepno = 1;
PARAMS.history=true;
PARAMS.drawpic=true;