posterior_sampler.m: trap case where record.ProposalCovariance is not filled (slice sampler)

matlab/posterior_sampler.m

@@ -156,10 +156,12 @@ else
         record.FunctionEvalPerIteration(offset+1:sum(nBlockPerCPU(1:j)))=fout(j).record.FunctionEvalPerIteration(offset+1:sum(nBlockPerCPU(1:j)));
         record.LastSeeds(offset+1:sum(nBlockPerCPU(1:j)))=fout(j).record.LastSeeds(offset+1:sum(nBlockPerCPU(1:j)));
         if j==1
+            if isfield(fout(j).record,'ProposalCovariance') && isfield(fout(j).record,'ProposalScaleVec')
                 record.ProposalCovariance=fout(j).record.ProposalCovariance;
                 record.ProposalScaleVec=fout(j).record.ProposalScaleVec;
             end
         end
+    end
     options_.parallel_info.parallel_recover = 0;
 end