dof

1 files changed, 6 insertions, 6 deletions

diff --git a/ministat.c b/ministat.c
index 076186d..94fa996 100644
--- a/ministat.c
+++ b/ministat.c
@@ -317,13 +317,13 @@ Vitals(struct dataset *ds, int flag)
 
 static double dof(struct dataset *a, struct dataset *b)
 {
+	double sa = Var(a) / a->sn;
+	double sb = Var(b) / b->sn;
 	double v;
 
-	v = Var(a) / a->sn + Var(b) / b->sn;
+	v = sa + sb;
 	v *= v;
-
-	v /= (Var(a) * Var(a) / (a->sn * a->sn * (a->sn - 1)) +
-	      (Var(b) * Var(b) / (b->sn * b->sn * (b->sn - 1))));
+	v /= sa * sa / (a->sn - 1) + sb * sb / (b->sn - 1);
 
 	return v;
 }
@@ -389,10 +389,10 @@ Relative(struct dataset *ds, struct dataset *rs, int confidx)
 			c = student[0][confidx];
 		else
 			c = student[v][confidx];
-		c *= sqrt(Var(ds)/ds->n - Var(rs)/rs->n);
+		c *= sqrt(Var(ds)/ds->n + Var(rs)/rs->n);
 
 		printf("Difference at %.1f%% confidence: %g +- %g (%.2f%% +- %.3f%%)\n", p,
-		       d, c, d / Avg(ds) * 100, c / Avg(ds) * 1000);
+		       d, c, d / Avg(ds) * 100, c / Avg(ds) * 100);
 	}
 }