From af25e7932e5e50d3a5516c695997fa59110106db Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Tue, 31 Jul 2012 10:25:29 -0400
Subject: [PATCH] Increase n_realizations every time accumulate_score is
 called.

---
 src/global.F90     |  4 ++--
 src/input_xml.F90  |  8 --------
 src/intercycle.F90 | 22 ++++++++--------------
 src/tally.F90      |  7 +++++++
 4 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/src/global.F90 b/src/global.F90
index a94548f5e5..dea0db4570 100644
--- a/src/global.F90
+++ b/src/global.F90
@@ -121,8 +121,8 @@ module global
   integer :: n_current_tallies     = 0 ! # of surface current tallies
 
   ! Normalization for statistics
-  integer :: n_realizations ! # of independent realizations
-  real(8) :: total_weight   ! total starting particle weight in realization
+  integer :: n_realizations = 0 ! # of independent realizations
+  real(8) :: total_weight       ! total starting particle weight in realization
 
   ! Flag for turning tallies on
   logical :: tallies_on
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index ec192e74f8..72a64a7758 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -461,14 +461,6 @@ contains
     ! batch
     if (trim(no_reduce_) == 'on') reduce_tallies = .false.
 
-    ! Determine number of realizations
-    if (reduce_tallies) then
-       n_realizations = n_active
-    else
-       n_realizations = n_active * n_procs
-    end if
-       
-
   end subroutine read_settings_xml
 
 !===============================================================================
diff --git a/src/intercycle.F90 b/src/intercycle.F90
index 3a155df508..0118bf5104 100644
--- a/src/intercycle.F90
+++ b/src/intercycle.F90
@@ -360,7 +360,6 @@ contains
 
   subroutine calculate_keff()
 
-    integer :: n       ! active batch number
     real(8) :: temp(2) ! used to reduce sum and sum_sq
 
     message = "Calculate batch keff..."
@@ -395,25 +394,19 @@ contains
           ! need to perform any more reductions and just take the values from
           ! global_tallies directly
 
-          ! Define number of realizations
-          n = current_batch - n_inactive
-
           ! Sample mean of keff
-          keff = global_tallies(K_ANALOG) % sum / n
+          keff = global_tallies(K_ANALOG) % sum / n_realizations
 
-          if (n > 1) then
+          if (n_realizations > 1) then
              ! Standard deviation of the sample mean of k
-             keff_std = sqrt((global_tallies(K_ANALOG) % sum_sq/n - &
-                  keff*keff)/(n - 1))
+             keff_std = sqrt((global_tallies(K_ANALOG) % sum_sq / &
+                  n_realizations - keff * keff) / (n_realizations - 1))
           end if
        else
           ! In this case, no reduce was ever done on global_tallies. Thus, we
           ! need to reduce the values in sum and sum^2 to get the sample mean
           ! and its standard deviation
 
-          ! Define number of realizations
-          n = (current_batch - n_inactive) * n_procs
-
 #ifdef MPI
           if (current_batch /= n_batches) then
              call MPI_REDUCE(global_tallies(K_ANALOG) % sum, temp, 2, &
@@ -428,11 +421,12 @@ contains
 #endif
 
           ! Sample mean of k
-          keff = temp(1) / n
+          keff = temp(1) / n_realizations
           
-          if (n > 1) then
+          if (n_realizations > 1) then
              ! Standard deviation of the sample mean of k
-             keff_std = sqrt((temp(2)/n - keff*keff)/(n - 1))
+             keff_std = sqrt((temp(2)/n_realizations - keff*keff) / &
+                  (n_realizations - 1))
           end if
        end if
 
diff --git a/src/tally.F90 b/src/tally.F90
index fa49364be1..955daf8380 100644
--- a/src/tally.F90
+++ b/src/tally.F90
@@ -1622,6 +1622,13 @@ contains
 #endif
 
     if (master .or. (.not. reduce_tallies)) then
+       ! Increase number of realizations
+       if (reduce_tallies) then
+          n_realizations = n_realizations + 1
+       else
+          n_realizations = n_realizations + n_procs
+       end if
+
        ! Accumulate scores for each tally
        do i = 1, n_tallies
           call accumulate_score(tallies(i) % scores)