--- /dev/null
+
+///////////////////////////////////////////////////////////////////////////
+// This program is free software: you can redistribute it and/or modify //
+// it under the terms of the version 3 of the GNU General Public License //
+// as published by the Free Software Foundation. //
+// //
+// This program is distributed in the hope that it will be useful, but //
+// WITHOUT ANY WARRANTY; without even the implied warranty of //
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU //
+// General Public License for more details. //
+// //
+// You should have received a copy of the GNU General Public License //
+// along with this program. If not, see <http://www.gnu.org/licenses/>. //
+// //
+// Written by Francois Fleuret, (C) IDIAP //
+// Contact <francois.fleuret@idiap.ch> for comments & bug reports //
+///////////////////////////////////////////////////////////////////////////
+
+#include "gaussian.h"
+
+Gaussian::Gaussian() {
+ _nb_samples = 0;
+ _sum = 0.0;
+ _sum_sq = 0.0;
+}
+
+void Gaussian::add_sample(scalar_t x) {
+ _nb_samples++;
+ _sum += x;
+ _sum_sq += x * x;
+}
+
+scalar_t Gaussian::expectation() {
+ return _sum / scalar_t(_nb_samples);
+}
+
+scalar_t Gaussian::variance() {
+ scalar_t e = _sum / scalar_t(_nb_samples);
+ return (_sum_sq - _sum * e) / scalar_t(_nb_samples - 1);
+}
+
+scalar_t Gaussian::standard_deviation() {
+ return sqrt(variance());
+}
+