Java Reference

Java Reference

AffineExpression.java
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1// Copyright 2010-2021 Google LLC
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14package com.google.ortools.sat;
15
17public final class AffineExpression implements LinearExpr {
18 private final int varIndex;
19 private final long coefficient;
20 private final long offset;
21
22 public AffineExpression(int varIndex, long coefficient, long offset) {
23 this.varIndex = varIndex;
24 this.coefficient = coefficient;
25 this.offset = offset;
26 }
27
28 // LinearArgument interface.
29 @Override
30 public LinearExpr build() {
31 return this;
32 }
33
34 // LinearExpr interface.
35 @Override
36 public int numElements() {
37 return 1;
38 }
39
40 @Override
41 public int getVariableIndex(int index) {
42 if (index != 0) {
43 throw new IllegalArgumentException("wrong index in LinearExpr.getIndex(): " + index);
44 }
45 return varIndex;
46 }
47
48 @Override
49 public long getCoefficient(int index) {
50 if (index != 0) {
51 throw new IllegalArgumentException("wrong index in LinearExpr.getCoefficient(): " + index);
52 }
53 return coefficient;
54 }
55
56 @Override
57 public long getOffset() {
58 return offset;
59 }
60}
A specialized linear expression: a * x + b.
long getCoefficient(int index)
Returns the ith coefficient.
AffineExpression(int varIndex, long coefficient, long offset)
int numElements()
Returns the number of terms (excluding the constant one) in this expression.
LinearExpr build()
Builds a linear expression.
long getOffset()
Returns the constant part of the expression.
int getVariableIndex(int index)
Returns the index of the ith variable.
A linear expression (sum (ai * xi) + b).
Definition: LinearExpr.java:19