mv libcpustats from frameworks/native to frameworks/av
OK to lose history
Change-Id: Ieca78edc5dfe479dd7ea48fe7e0f3c164356cee3
diff --git a/include/cpustats/CentralTendencyStatistics.h b/include/cpustats/CentralTendencyStatistics.h
new file mode 100644
index 0000000..21b6981
--- /dev/null
+++ b/include/cpustats/CentralTendencyStatistics.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _CENTRAL_TENDENCY_STATISTICS_H
+#define _CENTRAL_TENDENCY_STATISTICS_H
+
+#include <math.h>
+
+// Not multithread safe
+class CentralTendencyStatistics {
+
+public:
+
+ CentralTendencyStatistics() :
+ mMean(NAN), mMedian(NAN), mMinimum(INFINITY), mMaximum(-INFINITY), mN(0), mM2(0),
+ mVariance(NAN), mVarianceKnownForN(0), mStddev(NAN), mStddevKnownForN(0) { }
+
+ ~CentralTendencyStatistics() { }
+
+ // add x to the set of samples
+ void sample(double x);
+
+ // return the arithmetic mean of all samples so far
+ double mean() const { return mMean; }
+
+ // return the minimum of all samples so far
+ double minimum() const { return mMinimum; }
+
+ // return the maximum of all samples so far
+ double maximum() const { return mMaximum; }
+
+ // return the variance of all samples so far
+ double variance() const;
+
+ // return the standard deviation of all samples so far
+ double stddev() const;
+
+ // return the number of samples added so far
+ unsigned n() const { return mN; }
+
+ // reset the set of samples to be empty
+ void reset();
+
+private:
+ double mMean;
+ double mMedian;
+ double mMinimum;
+ double mMaximum;
+ unsigned mN; // number of samples so far
+ double mM2;
+
+ // cached variance, and n at time of caching
+ mutable double mVariance;
+ mutable unsigned mVarianceKnownForN;
+
+ // cached standard deviation, and n at time of caching
+ mutable double mStddev;
+ mutable unsigned mStddevKnownForN;
+
+};
+
+#endif // _CENTRAL_TENDENCY_STATISTICS_H