initialize new output argument regime_history in case of early return (due to error flags)

matlab/+occbin/IVF_core.m

@@ -92,6 +92,9 @@ for this_period=1:sample_length
         filtered_errs=NaN;
         error_code(1) = 304;
         error_code(4) = 1000;
+        if this_period == 1
+            regime_history(this_period) = [];
+        end
         if options_.occbin.likelihood.waitbar; dyn_waitbar_close(hh_fig); end
         return
     end

matlab/+occbin/IVF_posterior.m

@@ -58,6 +58,8 @@ trend_coeff = [];
 obs = dataset_.data;
 obs_list = options_.varobs(:);
 exit_flag   = 1;
+% initialize output argument in case of early return
+regime_history = [];
 
 
 if size(xparam1,1)<size(xparam1,2)