function [yellow] = yellow(r,sigma,t,S,T,E,eta,ti,orange)
%returns an array, on [0,ti]x[-m^2,m^2] with 
%ti^2+1 steps and 2m^2[exp(m^4)]+1 steps respectively,
%solving the ODE of Theorem 0.9. 
z=log(eta);
m=z^0.25;
square=m^2;
quart=m^4;
a=2*m*eta;
b=rem(a,1);
steps1=a-b;
nsteps1=steps1+1;
c=2*square*eta;
d=rem(c,1);
steps2=c-d;
nsteps2=steps2+1;
stepsize=1/eta;
steps3=ti^2;
nsteps3=steps3+1;
stepsizeti=1/ti;
x=linspace(-m,m,nsteps1);
k=(2*r)/sigma^2;
v=2/(sigma^2*ti);
w=rem(T,v);
T1=T-w;
k1=(0.5*ti*sigma^2*T1);
steps4=T1/v;
nsteps4=steps4+1;
hatg=orange(2,:);
x=orange(1,:);
t=linspace(0,ti,nsteps3);
[T,X]=meshgrid(t,x);
for (j=1:nsteps2)
    c(j)=((-m^2)*eta+(j-1))*stepsize;
    psi(j)=eta*(exp(pi*i*c(j))-1);
    phi(j)=psi(j)*psi(j);
end
for (j=1:nsteps2)
    for (t=1:k1+1)
   hatf(t,j)=hatg(j)*(1+phi(j)*stepsizeti)^(t+1);     
end
end
for (a=1:3)
    for (t=1:k1+1)
        for (j=1:nsteps2)
    if (a==1)
        yellow(a,t,j)=T(j,t);
    elseif (a==2)
        yellow(a,t,j)=X(j,t);
    else
        yellow(a,t,j)=hatf(t,j);
    
    end
end
    end

end




end
