-
Notifications
You must be signed in to change notification settings - Fork 205
/
BoundsOnRatiosInTupleSketchedSets.java
202 lines (176 loc) · 7.8 KB
/
BoundsOnRatiosInTupleSketchedSets.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.apache.datasketches;
import static org.apache.datasketches.Util.LONG_MAX_VALUE_AS_DOUBLE;
import org.apache.datasketches.tuple.Sketch;
import org.apache.datasketches.tuple.Summary;
/**
* This class is used to compute the bounds on the estimate of the ratio <i>B / A</i>, where:
* <ul>
* <li><i>A</i> is a Tuple Sketch of population <i>PopA</i>.</li>
* <li><i>B</i> is a Tuple or Theta Sketch of population <i>PopB</i> that is a subset of <i>A</i>,
* obtained by an intersection of <i>A</i> with some other Tuple or Theta Sketch <i>C</i>,
* which acts like a predicate or selection clause.</li>
* <li>The estimate of the ratio <i>PopB/PopA</i> is
* BoundsOnRatiosInThetaSketchedSets.getEstimateOfBoverA(<i>A, B</i>).</li>
* <li>The Upper Bound estimate on the ratio PopB/PopA is
* BoundsOnRatiosInThetaSketchedSets.getUpperBoundForBoverA(<i>A, B</i>).</li>
* <li>The Lower Bound estimate on the ratio PopB/PopA is
* BoundsOnRatiosInThetaSketchedSets.getLowerBoundForBoverA(<i>A, B</i>).</li>
* </ul>
* Note: The theta of <i>A</i> cannot be greater than the theta of <i>B</i>.
* If <i>B</i> is formed as an intersection of <i>A</i> and some other set <i>C</i>,
* then the theta of <i>B</i> is guaranteed to be less than or equal to the theta of <i>B</i>.
*
* @author Kevin Lang
* @author Lee Rhodes
* @author David Cromberge
*/
public final class BoundsOnRatiosInTupleSketchedSets {
private BoundsOnRatiosInTupleSketchedSets() {}
/**
* Gets the approximate lower bound for B over A based on a 95% confidence interval
* @param sketchA the Tuple sketch A with summary type <i>S</i>
* @param sketchB the Tuple sketch B with summary type <i>S</i>
* @param <S> Summary
* @return the approximate lower bound for B over A
*/
public static <S extends Summary> double getLowerBoundForBoverA(
final Sketch<S> sketchA,
final Sketch<S> sketchB) {
final long thetaLongA = sketchA.getThetaLong();
final long thetaLongB = sketchB.getThetaLong();
checkThetas(thetaLongA, thetaLongB);
final int countB = sketchB.getRetainedEntries();
final int countA = thetaLongB == thetaLongA
? sketchA.getRetainedEntries()
: sketchA.getCountLessThanThetaLong(thetaLongB);
if (countA <= 0) { return 0; }
final double f = thetaLongB / LONG_MAX_VALUE_AS_DOUBLE;
return BoundsOnRatiosInSampledSets.getLowerBoundForBoverA(countA, countB, f);
}
/**
* Gets the approximate lower bound for B over A based on a 95% confidence interval
* @param sketchA the Tuple sketch A with summary type <i>S</i>
* @param sketchB the Theta sketch B
* @param <S> Summary
* @return the approximate lower bound for B over A
*/
public static <S extends Summary> double getLowerBoundForBoverA(
final Sketch<S> sketchA,
final org.apache.datasketches.theta.Sketch sketchB) {
final long thetaLongA = sketchA.getThetaLong();
final long thetaLongB = sketchB.getThetaLong();
checkThetas(thetaLongA, thetaLongB);
final int countB = sketchB.getRetainedEntries();
final int countA = thetaLongB == thetaLongA
? sketchA.getRetainedEntries()
: sketchA.getCountLessThanThetaLong(thetaLongB);
if (countA <= 0) { return 0; }
final double f = thetaLongB / LONG_MAX_VALUE_AS_DOUBLE;
return BoundsOnRatiosInSampledSets.getLowerBoundForBoverA(countA, countB, f);
}
/**
* Gets the approximate upper bound for B over A based on a 95% confidence interval
* @param sketchA the Tuple sketch A with summary type <i>S</i>
* @param sketchB the Tuple sketch B with summary type <i>S</i>
* @param <S> Summary
* @return the approximate upper bound for B over A
*/
public static <S extends Summary> double getUpperBoundForBoverA(
final Sketch<S> sketchA,
final Sketch<S> sketchB) {
final long thetaLongA = sketchA.getThetaLong();
final long thetaLongB = sketchB.getThetaLong();
checkThetas(thetaLongA, thetaLongB);
final int countB = sketchB.getRetainedEntries();
final int countA = thetaLongB == thetaLongA
? sketchA.getRetainedEntries()
: sketchA.getCountLessThanThetaLong(thetaLongB);
if (countA <= 0) { return 1.0; }
final double f = thetaLongB / LONG_MAX_VALUE_AS_DOUBLE;
return BoundsOnRatiosInSampledSets.getUpperBoundForBoverA(countA, countB, f);
}
/**
* Gets the approximate upper bound for B over A based on a 95% confidence interval
* @param sketchA the Tuple sketch A with summary type <i>S</i>
* @param sketchB the Theta sketch B
* @param <S> Summary
* @return the approximate upper bound for B over A
*/
public static <S extends Summary> double getUpperBoundForBoverA(
final Sketch<S> sketchA,
final org.apache.datasketches.theta.Sketch sketchB) {
final long thetaLongA = sketchA.getThetaLong();
final long thetaLongB = sketchB.getThetaLong();
checkThetas(thetaLongA, thetaLongB);
final int countB = sketchB.getRetainedEntries(true);
final int countA = thetaLongB == thetaLongA
? sketchA.getRetainedEntries()
: sketchA.getCountLessThanThetaLong(thetaLongB);
if (countA <= 0) { return 1.0; }
final double f = thetaLongB / LONG_MAX_VALUE_AS_DOUBLE;
return BoundsOnRatiosInSampledSets.getUpperBoundForBoverA(countA, countB, f);
}
/**
* Gets the estimate for B over A
* @param sketchA the Tuple sketch A with summary type <i>S</i>
* @param sketchB the Tuple sketch B with summary type <i>S</i>
* @param <S> Summary
* @return the estimate for B over A
*/
public static <S extends Summary> double getEstimateOfBoverA(
final Sketch<S> sketchA,
final Sketch<S> sketchB) {
final long thetaLongA = sketchA.getThetaLong();
final long thetaLongB = sketchB.getThetaLong();
checkThetas(thetaLongA, thetaLongB);
final int countB = sketchB.getRetainedEntries();
final int countA = thetaLongB == thetaLongA
? sketchA.getRetainedEntries()
: sketchA.getCountLessThanThetaLong(thetaLongB);
if (countA <= 0) { return 0.5; }
return (double) countB / (double) countA;
}
/**
* Gets the estimate for B over A
* @param sketchA the Tuple sketch A with summary type <i>S</i>
* @param sketchB the Theta sketch B
* @param <S> Summary
* @return the estimate for B over A
*/
public static <S extends Summary> double getEstimateOfBoverA(
final Sketch<S> sketchA,
final org.apache.datasketches.theta.Sketch sketchB) {
final long thetaLongA = sketchA.getThetaLong();
final long thetaLongB = sketchB.getThetaLong();
checkThetas(thetaLongA, thetaLongB);
final int countB = sketchB.getRetainedEntries(true);
final int countA = thetaLongB == thetaLongA
? sketchA.getRetainedEntries()
: sketchA.getCountLessThanThetaLong(thetaLongB);
if (countA <= 0) { return 0.5; }
return (double) countB / (double) countA;
}
static void checkThetas(final long thetaLongA, final long thetaLongB) {
if (thetaLongB > thetaLongA) {
throw new SketchesArgumentException("ThetaLongB cannot be > ThetaLongA.");
}
}
}