--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/utilities/numberSeq.hpp Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+/**
+ ** This file contains a few classes that represent number sequence,
+ ** x1, x2, x3, ..., xN, and can calculate their avg, max, and sd.
+ **
+ ** Here's a quick description of the classes:
+ **
+ ** AbsSeq: abstract superclass
+ ** NumberSeq: the sequence is assumed to be very long and the
+ ** maximum, avg, sd, davg, and dsd are calculated over all its elements
+ ** TruncatedSeq: this class keeps track of the last L elements
+ ** of the sequence and calculates avg, max, and sd only over them
+ **/
+
+#define DEFAULT_ALPHA_VALUE 0.7
+
+class AbsSeq {
+private:
+ void init(double alpha);
+
+protected:
+ int _num; // the number of elements in the sequence
+ double _sum; // the sum of the elements in the sequence
+ double _sum_of_squares; // the sum of squares of the elements in the sequence
+
+ double _davg; // decaying average
+ double _dvariance; // decaying variance
+ double _alpha; // factor for the decaying average / variance
+
+ // This is what we divide with to get the average. In a standard
+ // number sequence, this should just be the number of elements in it.
+ virtual double total() const { return (double) _num; };
+
+public:
+ AbsSeq(double alpha = DEFAULT_ALPHA_VALUE);
+
+ virtual void add(double val); // adds a new element to the sequence
+ void add(unsigned val) { add((double) val); }
+ virtual double maximum() const = 0; // maximum element in the sequence
+ virtual double last() const = 0; // last element added in the sequence
+
+ // the number of elements in the sequence
+ int num() const { return _num; }
+ // the sum of the elements in the sequence
+ double sum() const { return _sum; }
+
+ double avg() const; // the average of the sequence
+ double variance() const; // the variance of the sequence
+ double sd() const; // the standard deviation of the sequence
+
+ double davg() const; // decaying average
+ double dvariance() const; // decaying variance
+ double dsd() const; // decaying "standard deviation"
+};
+
+class NumberSeq: public AbsSeq {
+private:
+ bool check_nums(NumberSeq* total, int n, NumberSeq** parts);
+
+protected:
+ double _last;
+ double _maximum; // keep track of maximum value
+
+public:
+ NumberSeq(double alpha = DEFAULT_ALPHA_VALUE);
+ NumberSeq(NumberSeq* total, int n_parts, NumberSeq** parts);
+
+ virtual void add(double val);
+ virtual double maximum() const { return _maximum; }
+ virtual double last() const { return _last; }
+};
+
+class TruncatedSeq: public AbsSeq {
+private:
+ enum PrivateConstants {
+ DefaultSeqLength = 10
+ };
+ void init();
+protected:
+ double *_sequence; // buffers the last L elements in the sequence
+ int _length; // this is L
+ int _next; // oldest slot in the array, i.e. next to be overwritten
+
+public:
+ // accepts a value for L
+ TruncatedSeq(int length = DefaultSeqLength,
+ double alpha = DEFAULT_ALPHA_VALUE);
+ virtual void add(double val);
+ virtual double maximum() const;
+ virtual double last() const; // the last value added to the sequence
+
+ double oldest() const; // the oldest valid value in the sequence
+ double predict_next() const; // prediction based on linear regression
+};