From faa44b24ef1e641121e951647bebc663423daf5b Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 14 May 2012 16:11:09 +1000
Subject: [PATCH] Add simple stat accumulator class

---
 Makefile.am |  2 ++
 stats.cpp   | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 stats.hpp   | 48 +++++++++++++++++++++++++++++++++++++
 3 files changed, 119 insertions(+)
 create mode 100644 stats.cpp
 create mode 100644 stats.hpp

diff --git a/Makefile.am b/Makefile.am
index 38bd7315..91b82719 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -82,6 +82,8 @@ UTIL_FILES   =		\
     signal.cpp		\
     signal.hpp		\
     si.hpp		\
+    stats.cpp		\
+    stats.hpp		\
     stream.cpp		\
     stream.hpp		\
     string.cpp		\
diff --git a/stats.cpp b/stats.cpp
new file mode 100644
index 00000000..c32b2dee
--- /dev/null
+++ b/stats.cpp
@@ -0,0 +1,69 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ * 
+ * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2010 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "stats.hpp"
+
+#include <cmath>
+#include <limits>
+
+
+template <typename T>
+util::stats::accumulator<T>::accumulator ():
+    min (std::numeric_limits<T>::max ()),
+    max (std::numeric_limits<T>::min ())
+{ ; }
+
+
+template <typename T>
+void
+util::stats::accumulator<T>::add (T val) {
+    min = std::min (val, min);
+    max = std::max (val, max);
+}
+
+
+template <typename T>
+void
+util::stats::accumulator<T>::add (const accumulator<T> &rhs) {
+    min = std::min (rhs.min, min);
+    max = std::max (rhs.max, max);
+}
+
+
+template <typename T>
+T
+util::stats::accumulator<T>::range (void) const
+    { return max - min; }
+
+
+template struct util::stats::accumulator<double>;
+template struct util::stats::accumulator<float>;
+
+
+template <typename T>
+std::ostream&
+util::stats::operator<< (std::ostream &os, const accumulator<T> &rhs) {
+    os << "(min: " << rhs.min << ", max: " << rhs.max << ")";
+    return os;
+}
+
+
+template std::ostream& util::stats::operator<< (std::ostream&, const accumulator<double> &);
+template std::ostream& util::stats::operator<< (std::ostream&, const accumulator<float > &);
+
diff --git a/stats.hpp b/stats.hpp
new file mode 100644
index 00000000..57a93c0e
--- /dev/null
+++ b/stats.hpp
@@ -0,0 +1,48 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ * 
+ * libgim 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 libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2010 Danny Robson <danny@nerdcruft.net>
+ */
+
+#ifndef __UTIL_STATS_HPP
+#define __UTIL_STATS_HPP
+
+#include <iostream>
+
+
+namespace util {
+    namespace stats {
+        // Undefined until at least one value has been added.
+
+        template <typename T>
+        struct accumulator {
+            accumulator ();
+
+            void add (T);
+            void add (const accumulator<T> &);
+
+            T min;
+            T max;
+
+            T range (void) const;
+        };
+
+        template <typename T>
+        std::ostream& operator<< (std::ostream&, const accumulator<T>&);
+    }
+}
+
+#endif