X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=foosrank.cpp;fp=foosrank.cpp;h=4b44706fe67fd77bcacadbfbe4093281a4c734b8;hb=6de5990c86e41173169db2dd974ff0332b9d0ee6;hp=374bc13a1067fb924f06d6b810aaccffe062feec;hpb=4be9512cbccded915f224620c6e43dc6e1be53fd;p=foosball

diff --git a/foosrank.cpp b/foosrank.cpp
index 374bc13..4b44706 100644
--- a/foosrank.cpp
+++ b/foosrank.cpp
@@ -122,9 +122,10 @@ static void compute_opponent_rating_pdf(int k, int a, double mu2, double sigma2,
 		func1[i].real() = func1[i].imag() = func2[i].real() = func2[i].imag() = 0.0;
 	}
 
+	double invsigma2 = 1.0 / sigma2;
 	for (int i = 0; i < sz; ++i) {
 		double x1 = 0.0 + h*i;
-		double z = (x1 - mu2)/sigma2;
+		double z = (x1 - mu2) * invsigma2;
 		func1[i].real() = exp(-(z*z/2.0));
 
 		double x2 = -3000.0 + h*i;
@@ -372,11 +373,12 @@ static void compute_new_double_rating(double mu1, double sigma1, double mu2, dou
 		double r1 = i * h;
 
 		// iterate over r2
+		double invsigma2 = 1.0 / sigma2;
 		for (unsigned j = 0; j < curve.size(); ++j) {
 			double r1plusr2 = curve[j].first;
 			double r2 = r1plusr2 - r1;
 
-			double z = (r2 - mu2) / sigma2;
+			double z = (r2 - mu2) * invsigma2;
 			double gaussian = exp(-(z*z/2.0));
 			sum += curve[j].second * gaussian;
 		}