diff --git a/src/rmn.cpp b/src/rmn.cpp
index a8e952b..6a09cfd 100644
--- a/src/rmn.cpp
+++ b/src/rmn.cpp
@@ -99,7 +99,7 @@ void calcSumZ(const arma::vec& z, const arma::vec& empty, const arma::uvec& s, a
 
     for (i = 0; i < (w - 1) && i < L; i++){
       sumZ(w, s(i)) += empty(i);
-      sumZ(arma::span(w - 1 - i, w - 1), s(i)) = z(arma::span(0, i));
+      sumZ(arma::span(w - 1 - i, w - 1), s(i)) += z(arma::span(0, i));
     }
 
   }
@@ -232,14 +232,14 @@ void estimate(
       calcSumZ(z[iContig], empty[iContig], s[iContig], sumZ);
     }
 
-
+    std::cout << sumZ << std::endl;
     for (iExperiment = 0; iExperiment < nExperiment; iExperiment++){
       sumU.zeros();
       for (iContig = 0; iContig < nContig; iContig++){
         calcSumU(meanU[iContig].slice(iExperiment), s[iContig], sumU);
       }
       mu.slice(iExperiment) = sumU / sumZ;
-      std::cout << mu.slice(iExperiment) << std::endl;
+      std::cout << sumU << std::endl;
     }
     // calculate lnEmPN
     // re-estimate z