1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/utilities/numberSeq.hpp Thu Jun 05 15:57:56 2008 -0700
1.3 @@ -0,0 +1,117 @@
1.4 +/*
1.5 + * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +/**
1.29 + ** This file contains a few classes that represent number sequence,
1.30 + ** x1, x2, x3, ..., xN, and can calculate their avg, max, and sd.
1.31 + **
1.32 + ** Here's a quick description of the classes:
1.33 + **
1.34 + ** AbsSeq: abstract superclass
1.35 + ** NumberSeq: the sequence is assumed to be very long and the
1.36 + ** maximum, avg, sd, davg, and dsd are calculated over all its elements
1.37 + ** TruncatedSeq: this class keeps track of the last L elements
1.38 + ** of the sequence and calculates avg, max, and sd only over them
1.39 + **/
1.40 +
1.41 +#define DEFAULT_ALPHA_VALUE 0.7
1.42 +
1.43 +class AbsSeq {
1.44 +private:
1.45 + void init(double alpha);
1.46 +
1.47 +protected:
1.48 + int _num; // the number of elements in the sequence
1.49 + double _sum; // the sum of the elements in the sequence
1.50 + double _sum_of_squares; // the sum of squares of the elements in the sequence
1.51 +
1.52 + double _davg; // decaying average
1.53 + double _dvariance; // decaying variance
1.54 + double _alpha; // factor for the decaying average / variance
1.55 +
1.56 + // This is what we divide with to get the average. In a standard
1.57 + // number sequence, this should just be the number of elements in it.
1.58 + virtual double total() const { return (double) _num; };
1.59 +
1.60 +public:
1.61 + AbsSeq(double alpha = DEFAULT_ALPHA_VALUE);
1.62 +
1.63 + virtual void add(double val); // adds a new element to the sequence
1.64 + void add(unsigned val) { add((double) val); }
1.65 + virtual double maximum() const = 0; // maximum element in the sequence
1.66 + virtual double last() const = 0; // last element added in the sequence
1.67 +
1.68 + // the number of elements in the sequence
1.69 + int num() const { return _num; }
1.70 + // the sum of the elements in the sequence
1.71 + double sum() const { return _sum; }
1.72 +
1.73 + double avg() const; // the average of the sequence
1.74 + double variance() const; // the variance of the sequence
1.75 + double sd() const; // the standard deviation of the sequence
1.76 +
1.77 + double davg() const; // decaying average
1.78 + double dvariance() const; // decaying variance
1.79 + double dsd() const; // decaying "standard deviation"
1.80 +};
1.81 +
1.82 +class NumberSeq: public AbsSeq {
1.83 +private:
1.84 + bool check_nums(NumberSeq* total, int n, NumberSeq** parts);
1.85 +
1.86 +protected:
1.87 + double _last;
1.88 + double _maximum; // keep track of maximum value
1.89 +
1.90 +public:
1.91 + NumberSeq(double alpha = DEFAULT_ALPHA_VALUE);
1.92 + NumberSeq(NumberSeq* total, int n_parts, NumberSeq** parts);
1.93 +
1.94 + virtual void add(double val);
1.95 + virtual double maximum() const { return _maximum; }
1.96 + virtual double last() const { return _last; }
1.97 +};
1.98 +
1.99 +class TruncatedSeq: public AbsSeq {
1.100 +private:
1.101 + enum PrivateConstants {
1.102 + DefaultSeqLength = 10
1.103 + };
1.104 + void init();
1.105 +protected:
1.106 + double *_sequence; // buffers the last L elements in the sequence
1.107 + int _length; // this is L
1.108 + int _next; // oldest slot in the array, i.e. next to be overwritten
1.109 +
1.110 +public:
1.111 + // accepts a value for L
1.112 + TruncatedSeq(int length = DefaultSeqLength,
1.113 + double alpha = DEFAULT_ALPHA_VALUE);
1.114 + virtual void add(double val);
1.115 + virtual double maximum() const;
1.116 + virtual double last() const; // the last value added to the sequence
1.117 +
1.118 + double oldest() const; // the oldest valid value in the sequence
1.119 + double predict_next() const; // prediction based on linear regression
1.120 +};
