function z = getsir(b,xq)
global N beta gamma

gamma=b(1);
beta=b(2);
N=3.3E8;
NI=1;

[t,y]=ode15s('sircovf',[0,xq(end)],[N-NI,NI,0]);

z=interp1(t,y(:,2),xq);



%M=length(x);
%z(1)=NI;
%r(1)=0;
%s(1)=N-NI;
%for k=2:M
%    t0=x(k-1);
%    tf=x(k);
%    [t,y]=ode15s('sircovf',[t0,tf],[s(k-1),z(k-1),r(k-1)]);
%    s(k)=y(end,1);
%    z(k)=y(end,2);
%    r(k)=y(end,3);
%end