Stat summation fixup
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/stat.c b/stat.c
index 5470c87..07c9b62 100644
--- a/stat.c
+++ b/stat.c
@@ -579,8 +579,8 @@
mean = src->mean;
S = src->S;
} else {
- mean = ((src->mean * (double) nr) + dst->mean) / ((double) nr + 1.0);
- S = ((src->S * (double) nr) + dst->S) / ((double) nr + 1.0);
+ mean = ((src->mean * (double) (nr - 1)) + dst->mean) / ((double) nr);
+ S = ((src->S * (double) (nr - 1)) + dst->S) / ((double) nr);
}
dst->mean = mean;