BitChromosome.java

1 
package net.bmahe.genetics4j.core.chromosomes;
2
3 
import java.util.BitSet;
4 
import java.util.Objects;
5
6 
import org.apache.commons.lang3.Validate;
7
8 
/**
9 
 * A chromosome implementation that represents genetic information as a sequence of bits.
10 
 *
11 
 * <p>BitChromosome is commonly used for binary optimization problems, feature selection, and any application where the
12 
 * solution can be encoded as a bit string. Each bit (allele) can be either 0 or 1, representing boolean choices or
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 * binary features.
14 
 *
15 
 * <p>This implementation is immutable and uses a {@link BitSet} for efficient storage and manipulation of the bit
16 
 * sequence.
17 
 *
18 
 * <p>Common use cases include:
19 
 * <ul>
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 * <li>Binary optimization problems (knapsack, subset selection)</li>
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 * <li>Feature selection in machine learning</li>
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 * <li>Boolean satisfiability problems</li>
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 * <li>Circuit design and logic optimization</li>
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 * </ul>
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 *
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 * @see Chromosome
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 * @see java.util.BitSet
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 */
29 
public class BitChromosome implements Chromosome {
30
31 
	private final int numBits;
32 
	private final BitSet bitSet;
33
34 
	/**
35 
	 * Creates a new bit chromosome with the specified number of bits and initial values.
36 
	 *
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	 * @param _numBits the number of bits in this chromosome, must be positive
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	 * @param _bitSet  the initial bit values for this chromosome
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	 * @throws IllegalArgumentException if numBits is zero or negative, if bitSet is null, or if numBits exceeds the
40 
	 *                                  bitSet size
41 
	 */
42 
	public BitChromosome(final int _numBits, final BitSet _bitSet) {
43 
		Validate.isTrue(_numBits > 0, "numBits can't be zero or negative");
44 
		Objects.requireNonNull(_bitSet);
45 
		Validate.isTrue(_numBits <= _bitSet.size());
46
47 1 1. <init> : Removed assignment to member variable numBits → KILLED
 
		this.numBits = _numBits;
48 2 1. <init> : Removed assignment to member variable bitSet → KILLED
2. <init> : removed call to java/util/BitSet::<init> → KILLED
 
		this.bitSet = new BitSet(numBits);
49 1 1. <init> : removed call to java/util/BitSet::or → KILLED
 
		this.bitSet.or(_bitSet);
50 
	}
51
52 
	@Override
53 
	public int getNumAlleles() {
54 1 1. getNumAlleles : replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getNumAlleles → KILLED
 
		return numBits;
55 
	}
56
57 
	/**
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	 * Returns the bit value at the specified index.
59 
	 *
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	 * @param index the index of the bit to retrieve (0-based)
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	 * @return {@code true} if the bit is set (1), {@code false} if clear (0)
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	 * @throws IllegalArgumentException if index is negative or greater than or equal to numBits
63 
	 */
64 
	public boolean getBit(final int index) {
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		Validate.isTrue(index >= 0);
66 
		Validate.isTrue(index < numBits);
67
68 3 1. getBit : removed call to java/util/BitSet::get → KILLED
2. getBit : replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getBit → KILLED
3. getBit : replaced boolean return with false for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getBit → KILLED
 
		return bitSet.get(index);
69 
	}
70
71 
	/**
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	 * Returns the underlying BitSet containing all bit values.
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	 *
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	 * <p>The returned BitSet is a copy and modifications to it will not affect this chromosome.
75 
	 *
76 
	 * @return a BitSet containing the bit values of this chromosome
77 
	 */
78 
	public BitSet getBitSet() {
79 1 1. getBitSet : replaced return value with null for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getBitSet → KILLED
 
		return bitSet;
80 
	}
81
82 
	/**
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	 * Returns the number of bits set to 1 in this chromosome.
84 
	 *
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	 * <p>This method counts all bits that are set to true (1) in the chromosome's bit sequence.
86 
	 *
87 
	 * @return the count of bits set to 1, ranging from 0 to numBits
88 
	 */
89 
	public int countOnes() {
90 2 1. countOnes : replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::countOnes → KILLED
2. countOnes : removed call to java/util/BitSet::cardinality → KILLED
 
		return bitSet.cardinality();
91 
	}
92
93 
	/**
94 
	 * Returns the number of bits set to 0 in this chromosome.
95 
	 *
96 
	 * <p>This method counts all bits that are set to false (0) in the chromosome's bit sequence. This is the complement
97 
	 * of {@link #countOnes()}.
98 
	 *
99 
	 * @return the count of bits set to 0, ranging from 0 to numBits
100 
	 * @see #countOnes()
101 
	 */
102 
	public int countZeros() {
103 3 1. countZeros : replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::countZeros → KILLED
2. countZeros : removed call to net/bmahe/genetics4j/core/chromosomes/BitChromosome::countOnes → KILLED
3. countZeros : Replaced integer subtraction with addition → KILLED
 
		return numBits - countOnes();
104 
	}
105
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	@Override
107 
	public int hashCode() {
108 1 1. hashCode : Substituted 31 with 32 → NO_COVERAGE
 
		final int prime = 31;
109 1 1. hashCode : Substituted 1 with 0 → NO_COVERAGE
 
		int result = 1;
110 8 1. hashCode : Replaced integer addition with subtraction → NO_COVERAGE
2. hashCode : negated conditional → NO_COVERAGE
3. hashCode : Substituted 31 with 32 → NO_COVERAGE
4. hashCode : removed conditional - replaced equality check with true → NO_COVERAGE
5. hashCode : removed conditional - replaced equality check with false → NO_COVERAGE
6. hashCode : Substituted 0 with 1 → NO_COVERAGE
7. hashCode : Replaced integer multiplication with division → NO_COVERAGE
8. hashCode : removed call to java/util/BitSet::hashCode → NO_COVERAGE
 
		result = prime * result + ((bitSet == null) ? 0 : bitSet.hashCode());
111 3 1. hashCode : Replaced integer addition with subtraction → NO_COVERAGE
2. hashCode : Substituted 31 with 32 → NO_COVERAGE
3. hashCode : Replaced integer multiplication with division → NO_COVERAGE
 
		result = prime * result + numBits;
112 1 1. hashCode : replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::hashCode → NO_COVERAGE
 
		return result;
113 
	}
114
115 
	@Override
116 
	public boolean equals(Object obj) {
117 2 1. equals : negated conditional → SURVIVED
2. equals : removed conditional - replaced equality check with true → SURVIVED
 
		if (this == obj)
118 2 1. equals : Substituted 1 with 0 → KILLED
2. equals : replaced boolean return with false for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → KILLED
 
			return true;
119 3 1. equals : removed conditional - replaced equality check with false → SURVIVED
2. equals : removed conditional - replaced equality check with true → KILLED
3. equals : negated conditional → KILLED
 
		if (obj == null)
120 2 1. equals : replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE
2. equals : Substituted 0 with 1 → NO_COVERAGE
 
			return false;
121 5 1. equals : removed call to java/lang/Object::getClass → KILLED
2. equals : removed conditional - replaced equality check with true → KILLED
3. equals : removed conditional - replaced equality check with false → KILLED
4. equals : negated conditional → KILLED
5. equals : removed call to java/lang/Object::getClass → KILLED
 
		if (getClass() != obj.getClass())
122 2 1. equals : replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → SURVIVED
2. equals : Substituted 0 with 1 → SURVIVED
 
			return false;
123 
		BitChromosome other = (BitChromosome) obj;
124 3 1. equals : removed conditional - replaced equality check with false → SURVIVED
2. equals : removed conditional - replaced equality check with true → KILLED
3. equals : negated conditional → KILLED
 
		if (bitSet == null) {
125 3 1. equals : removed conditional - replaced equality check with false → NO_COVERAGE
2. equals : removed conditional - replaced equality check with true → NO_COVERAGE
3. equals : negated conditional → NO_COVERAGE
 
			if (other.bitSet != null)
126 2 1. equals : Substituted 0 with 1 → NO_COVERAGE
2. equals : replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE
 
				return false;
127 4 1. equals : removed conditional - replaced equality check with false → SURVIVED
2. equals : removed conditional - replaced equality check with true → KILLED
3. equals : negated conditional → KILLED
4. equals : removed call to java/util/BitSet::equals → KILLED
 
		} else if (!bitSet.equals(other.bitSet))
128 2 1. equals : replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE
2. equals : Substituted 0 with 1 → NO_COVERAGE
 
			return false;
129 3 1. equals : removed conditional - replaced equality check with false → SURVIVED
2. equals : negated conditional → KILLED
3. equals : removed conditional - replaced equality check with true → KILLED
 
		if (numBits != other.numBits)
130 2 1. equals : replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE
2. equals : Substituted 0 with 1 → NO_COVERAGE
 
			return false;
131 2 1. equals : replaced boolean return with false for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → KILLED
2. equals : Substituted 1 with 0 → KILLED
 
		return true;
132 
	}
133
134 
	@Override
135 
	public String toString() {
136 2 1. toString : removed call to java/lang/String::valueOf → SURVIVED
2. toString : replaced return value with "" for net/bmahe/genetics4j/core/chromosomes/BitChromosome::toString → SURVIVED
 
		return "BitChromosome [numBits=" + numBits + ", bitSet=" + bitSet + "]";
137 
	}
138 
}

Mutations

47

1.1
Location : <init>
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] Removed assignment to member variable numBits → KILLED

48

1.1
Location : <init>
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] Removed assignment to member variable bitSet → KILLED

2.2
Location : <init>
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] removed call to java/util/BitSet::<init> → KILLED

49

1.1
Location : <init>
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] removed call to java/util/BitSet::or → KILLED

54

1.1
Location : getNumAlleles
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getNumAlleles → KILLED

68

1.1
Location : getBit
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed call to java/util/BitSet::get → KILLED

2.2
Location : getBit
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getBit → KILLED

3.3
Location : getBit
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] replaced boolean return with false for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getBit → KILLED

79

1.1
Location : getBitSet
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] replaced return value with null for net/bmahe/genetics4j/core/chromosomes/BitChromosome::getBitSet → KILLED

90

1.1
Location : countOnes
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::countOnes → KILLED

2.2
Location : countOnes
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] removed call to java/util/BitSet::cardinality → KILLED

103

1.1
Location : countZeros
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosEmpty()] replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::countZeros → KILLED

2.2
Location : countZeros
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] removed call to net/bmahe/genetics4j/core/chromosomes/BitChromosome::countOnes → KILLED

3.3
Location : countZeros
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:countZerosAll()] Replaced integer subtraction with addition → KILLED

108

1.1
Location : hashCode
Killed by : none Substituted 31 with 32 → NO_COVERAGE

109

1.1
Location : hashCode
Killed by : none Substituted 1 with 0 → NO_COVERAGE

110

1.1
Location : hashCode
Killed by : none Replaced integer addition with subtraction → NO_COVERAGE

2.2
Location : hashCode
Killed by : none negated conditional → NO_COVERAGE

3.3
Location : hashCode
Killed by : none Substituted 31 with 32 → NO_COVERAGE

4.4
Location : hashCode
Killed by : none removed conditional - replaced equality check with true → NO_COVERAGE

5.5
Location : hashCode
Killed by : none removed conditional - replaced equality check with false → NO_COVERAGE

6.6
Location : hashCode
Killed by : none Substituted 0 with 1 → NO_COVERAGE

7.7
Location : hashCode
Killed by : none Replaced integer multiplication with division → NO_COVERAGE

8.8
Location : hashCode
Killed by : none removed call to java/util/BitSet::hashCode → NO_COVERAGE

111

1.1
Location : hashCode
Killed by : none Replaced integer addition with subtraction → NO_COVERAGE

2.2
Location : hashCode
Killed by : none Substituted 31 with 32 → NO_COVERAGE

3.3
Location : hashCode
Killed by : none Replaced integer multiplication with division → NO_COVERAGE

112

1.1
Location : hashCode
Killed by : none replaced int return with 0 for net/bmahe/genetics4j/core/chromosomes/BitChromosome::hashCode → NO_COVERAGE

117

1.1
Location : equals
Killed by : none negated conditional → SURVIVED Covering tests

2.2
Location : equals
Killed by : none removed conditional - replaced equality check with true → SURVIVED Covering tests

118

1.1
Location : equals
Killed by : net.bmahe.genetics4j.core.GenotypeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.GenotypeTest]/[method:simple()] Substituted 1 with 0 → KILLED

2.2
Location : equals
Killed by : net.bmahe.genetics4j.core.GenotypeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.GenotypeTest]/[method:simple()] replaced boolean return with false for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → KILLED

119

1.1
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed conditional - replaced equality check with true → KILLED

2.2
Location : equals
Killed by : none removed conditional - replaced equality check with false → SURVIVED Covering tests

3.3
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] negated conditional → KILLED

120

1.1
Location : equals
Killed by : none replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE

2.2
Location : equals
Killed by : none Substituted 0 with 1 → NO_COVERAGE

121

1.1
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed call to java/lang/Object::getClass → KILLED

2.2
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed conditional - replaced equality check with true → KILLED

3.3
Location : equals
Killed by : net.bmahe.genetics4j.core.GenotypeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.GenotypeTest]/[method:simple()] removed conditional - replaced equality check with false → KILLED

4.4
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] negated conditional → KILLED

5.5
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed call to java/lang/Object::getClass → KILLED

122

1.1
Location : equals
Killed by : none replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → SURVIVED Covering tests

2.2
Location : equals
Killed by : none Substituted 0 with 1 → SURVIVED Covering tests

124

1.1
Location : equals
Killed by : none removed conditional - replaced equality check with false → SURVIVED Covering tests

2.2
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed conditional - replaced equality check with true → KILLED

3.3
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] negated conditional → KILLED

125

1.1
Location : equals
Killed by : none removed conditional - replaced equality check with false → NO_COVERAGE

2.2
Location : equals
Killed by : none removed conditional - replaced equality check with true → NO_COVERAGE

3.3
Location : equals
Killed by : none negated conditional → NO_COVERAGE

126

1.1
Location : equals
Killed by : none Substituted 0 with 1 → NO_COVERAGE

2.2
Location : equals
Killed by : none replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE

127

1.1
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed conditional - replaced equality check with true → KILLED

2.2
Location : equals
Killed by : none removed conditional - replaced equality check with false → SURVIVED Covering tests

3.3
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] negated conditional → KILLED

4.4
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed call to java/util/BitSet::equals → KILLED

128

1.1
Location : equals
Killed by : none replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE

2.2
Location : equals
Killed by : none Substituted 0 with 1 → NO_COVERAGE

129

1.1
Location : equals
Killed by : none removed conditional - replaced equality check with false → SURVIVED Covering tests

2.2
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] negated conditional → KILLED

3.3
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] removed conditional - replaced equality check with true → KILLED

130

1.1
Location : equals
Killed by : none replaced boolean return with true for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → NO_COVERAGE

2.2
Location : equals
Killed by : none Substituted 0 with 1 → NO_COVERAGE

131

1.1
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] replaced boolean return with false for net/bmahe/genetics4j/core/chromosomes/BitChromosome::equals → KILLED

2.2
Location : equals
Killed by : net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.core.chromosomes.BitChromosomeTest]/[method:simple()] Substituted 1 with 0 → KILLED

136

1.1
Location : toString
Killed by : none removed call to java/lang/String::valueOf → SURVIVED Covering tests

2.2
Location : toString
Killed by : none replaced return value with "" for net/bmahe/genetics4j/core/chromosomes/BitChromosome::toString → SURVIVED Covering tests

Active mutators

Tests examined


Report generated by PIT 1.20.3