关于dynare求助，万分感谢！

自己有点糊里糊涂的，不太懂loss function。写的code总是出现DYNARE: preprocessing failed。求大神赐教，非常感谢！

var x pi R r u;

varexo e_r e_u;

parameters sigma beta kappa omega rho_r rho_u mu1 mu2 gamma theta;

sigma = 1.5;

beta = 0.995;

kappa = 0.02;

omega = 0.5;

rho_r = 0.5;

rho_u = 0.5;

mu1 = 1.5;

mu2 = 0.13;

gamma = 0.5;

theta = {0, 0.5, 1};

model(linear);

x = x(+1)-(1/sigma)*(R-pi(+1)-r);

pi = beta*(1-theta)*pi(+1)+theta*pi(-1)+kappa*x+u;

R = mu1*pi+mu2*x;

r = rho_r*r(-1)+e_r;

u = rho_u*u(-1)+e_u;

end;

shocks;

var e_r; stderr 1;

var e_u; stderr 1;

end;

stoch_simul(oder=1);

Loss = (1/2)*(oo_.var(pi, pi)+omega*oo_.var(x,x)+gamma*oo_.var(R,R));

求大神帮忙不知道theta是不是不能同时写三个数，我将theta改为0之后显示：
Index in position 1 is invalid. Array indices must be positive integers or logical
values.

Error in work (line 163)
Loss = (1/2)*(oo_.var(pi, pi)+omega*oo_.var(x,x)+gamma*oo_.var(R,R));

Error in dynare (line 235)
evalin('base',fname) ;