Added input to pass sequence of shocks.

matlab/simul_backward_nonlinear_model.m

-function DynareOutput = simul_backward_nonlinear_model(initial_conditions, sample_size, DynareOptions, DynareModel, DynareOutput)
+function DynareOutput = simul_backward_nonlinear_model(initial_conditions, sample_size, DynareOptions, DynareModel, DynareOutput, innovations)
 
 %@info:
 %! @deftypefn {Function File} {@var{DynareOutput} =} simul_backward_nonlinear_model (@var{sample_size},@var{DynareOptions}, @var{DynareModel}, @var{DynareOutput})
@@ -55,6 +55,7 @@ if DynareModel.maximum_lead
     error(['simul_backward_nonlinear_model:: The specified model is not backward looking!'])
 end
 
+if nargin<6
     % Set the covariance matrix of the structural innovations.
     variances = diag(DynareModel.Sigma_e);
     number_of_shocks = length(DynareModel.Sigma_e);
@@ -80,6 +81,9 @@ end
     DynareOutput.exo_simul = zeros(sample_size,number_of_shocks);
     DynareOutput.exo_simul(:,positive_var_indx) = DynareOutput.bnlms.shocks;
     DynareOutput.exo_simul = [zeros(1,number_of_shocks); DynareOutput.exo_simul];
+else
+    DynareOutput.exo_simul = innovations;
+end
 
 % Get usefull vector of indices.
 ny0 = nnz(DynareModel.lead_lag_incidence(2,:));