Activations.java

package net.bmahe.genetics4j.neat;

import java.util.function.Function;

/**
 * Utility class providing common activation functions for NEAT (NeuroEvolution of Augmenting Topologies) neural networks.
 * 
 * <p>Activations contains a collection of mathematical functions commonly used as activation functions
 * in neural networks. These functions transform the weighted sum of inputs at each node into the node's
 * output value, introducing non-linearity that enables neural networks to learn complex patterns.
 * 
 * <p>Available activation functions:
 * <ul>
 * <li><strong>Linear</strong>: Simple linear transformation with slope and bias parameters</li>
 * <li><strong>Sigmoid</strong>: Logistic function providing smooth transition between 0 and 1</li>
 * <li><strong>Hyperbolic tangent</strong>: Smooth function providing output between -1 and 1</li>
 * <li><strong>Identity</strong>: Pass-through function for linear networks</li>
 * <li><strong>NEAT paper</strong>: Sigmoid variant with specific parameters from original NEAT research</li>
 * </ul>
 * 
 * <p>Function variations:
 * <ul>
 * <li><strong>Float versions</strong>: Optimized for float precision networks</li>
 * <li><strong>Double versions</strong>: Higher precision for sensitive applications</li>
 * <li><strong>Parameterized versions</strong>: Customizable function parameters</li>
 * <li><strong>Pre-configured versions</strong>: Common parameter combinations</li>
 * </ul>
 * 
 * <p>Common usage patterns:
 * <pre>{@code
 * // Use standard sigmoid activation
 * FeedForwardNetwork network = new FeedForwardNetwork(
 *     inputNodes, outputNodes, connections, Activations::sigmoid
 * );
 * 
 * // Custom sigmoid with different steepness
 * Function<Double, Double> customSigmoid = Activations.sigmoid(2.0);
 * FeedForwardNetwork steeperNetwork = new FeedForwardNetwork(
 *     inputNodes, outputNodes, connections, customSigmoid
 * );
 * 
 * // Hyperbolic tangent for outputs in [-1, 1] range
 * FeedForwardNetwork tanhNetwork = new FeedForwardNetwork(
 *     inputNodes, outputNodes, connections, Activations::tanh
 * );
 * 
 * // Linear activation for regression problems
 * FeedForwardNetwork linearNetwork = new FeedForwardNetwork(
 *     inputNodes, outputNodes, connections, Activations::identity
 * );
 * 
 * // Float versions for memory efficiency
 * Function<Float, Float> floatSigmoid = Activations.sigmoidFloat;
 * }</pre>
 * 
 * <p>Activation function characteristics:
 * <ul>
 * <li><strong>Sigmoid</strong>: Smooth, bounded [0,1], good for binary classification</li>
 * <li><strong>Tanh</strong>: Smooth, bounded [-1,1], zero-centered, often preferred over sigmoid</li>
 * <li><strong>Linear</strong>: Unbounded, preserves gradients, suitable for regression</li>
 * <li><strong>Identity</strong>: No transformation, useful for pass-through connections</li>
 * </ul>
 * 
 * <p>Performance considerations:
 * <ul>
 * <li><strong>Float vs Double</strong>: Float versions use less memory and may be faster</li>
 * <li><strong>Function references</strong>: Pre-defined functions avoid object creation</li>
 * <li><strong>Mathematical operations</strong>: Optimized implementations for common cases</li>
 * <li><strong>Branch prediction</strong>: Simple functions improve CPU branch prediction</li>
 * </ul>
 * 
 * <p>Integration with NEAT evolution:
 * <ul>
 * <li><strong>Network evaluation</strong>: Applied to hidden and output nodes during forward propagation</li>
 * <li><strong>Fitness computation</strong>: Affects network behavior and resulting fitness</li>
 * <li><strong>Gradient flow</strong>: Function choice impacts learning and evolution dynamics</li>
 * <li><strong>Problem matching</strong>: Different problems benefit from different activation functions</li>
 * </ul>
 * 
 * @see FeedForwardNetwork
 * @see NeatChromosome
 * @see Function
 */
public class Activations {

	private Activations() {
	}

	/**
	 * Creates a linear activation function with specified slope and bias for float values.
	 * 
	 * <p>The linear function computes: f(x) = a * x + b
	 * 
	 * @param a the slope parameter
	 * @param b the bias parameter
	 * @return a linear activation function
	 */
	public static Function<Float, Float> linearFloat(final float a, final float b) {
		return (x) -> a * x + b;
	}

	/**
	 * Creates a linear activation function with specified slope and bias for double values.
	 * 
	 * <p>The linear function computes: f(x) = a * x + b
	 * 
	 * @param a the slope parameter
	 * @param b the bias parameter
	 * @return a linear activation function
	 */
	public static Function<Double, Double> linear(final double a, final double b) {
		return (x) -> a * x + b;
	}

	/**
	 * Creates a sigmoid activation function with specified steepness for float values.
	 * 
	 * <p>The sigmoid function computes: f(x) = 1 / (1 + exp(-a * x))
	 * <p>Output range: (0, 1)
	 * 
	 * @param a the steepness parameter (higher values create steeper transitions)
	 * @return a sigmoid activation function
	 */
	public static Function<Float, Float> sigmoidFloat(final float a) {
		return (x) -> 1.0f / (1.0f + (float) Math.exp(-a * x));
	}

	/**
	 * Creates a sigmoid activation function with specified steepness for double values.
	 * 
	 * <p>The sigmoid function computes: f(x) = 1 / (1 + exp(-a * x))
	 * <p>Output range: (0, 1)
	 * 
	 * @param a the steepness parameter (higher values create steeper transitions)
	 * @return a sigmoid activation function
	 */
	public static Function<Double, Double> sigmoid(final double a) {
		return (x) -> 1.0d / (1.0d + Math.exp(-a * x));
	}

	/** Standard sigmoid activation function for float values (steepness = 1.0). */
	public static Function<Float, Float> sigmoidFloat = sigmoidFloat(1.0f);
	
	/** Standard sigmoid activation function for double values (steepness = 1.0). */
	public static Function<Double, Double> sigmoid = sigmoid(1.0d);

	/** Identity activation function for float values (f(x) = x). */
	public static Function<Float, Float> identityFloat = linearFloat(1.0f, 0.0f);
	
	/** Identity activation function for double values (f(x) = x). */
	public static Function<Double, Double> identity = linear(1.0d, 0.0d);

	/** Hyperbolic tangent activation function for float values. Output range: (-1, 1). */
	public static Function<Float, Float> tanhFloat = (x) -> (float) Math.tanh(x);
	
	/** Hyperbolic tangent activation function for double values. Output range: (-1, 1). */
	public static Function<Double, Double> tanh = (x) -> Math.tanh(x);

	/** Sigmoid activation function with steepness 4.9 as used in the original NEAT paper (float version). */
	public static Function<Float, Float> neatPaperFloat = sigmoidFloat(4.9f);
	
	/** Sigmoid activation function with steepness 4.9 as used in the original NEAT paper (double version). */
	public static Function<Double, Double> neatPaper = sigmoid(4.9f);
}








Active mutators

CONDITIONALS_BOUNDARY
CONSTRUCTOR_CALLS
EMPTY_RETURNS
EXPERIMENTAL_ARGUMENT_PROPAGATION
EXPERIMENTAL_BIG_DECIMAL
EXPERIMENTAL_BIG_INTEGER
EXPERIMENTAL_MEMBER_VARIABLE
EXPERIMENTAL_NAKED_RECEIVER
EXPERIMENTAL_REMOVE_SWITCH_MUTATOR_[0-99]
EXPERIMENTAL_SWITCH
FALSE_RETURNS
INCREMENTS
INLINE_CONSTS
INVERT_NEGS
MATH
NEGATE_CONDITIONALS
NON_VOID_METHOD_CALLS
NULL_RETURNS
PRIMITIVE_RETURNS
REMOVE_CONDITIONALS_EQUAL_ELSE
REMOVE_CONDITIONALS_EQUAL_IF
REMOVE_CONDITIONALS_ORDER_ELSE
REMOVE_CONDITIONALS_ORDER_IF
REMOVE_INCREMENTS
TRUE_RETURNS
VOID_METHOD_CALLS

Tests examined

net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyLinear()] (3 ms)
net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNotNull()] (34 ms)
net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] (2 ms)
net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] (6 ms)
net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] (2 ms)

Report generated by PIT 1.19.6

1		package net.bmahe.genetics4j.neat;
2
3		import java.util.function.Function;
4
5		/**
6		* Utility class providing common activation functions for NEAT (NeuroEvolution of Augmenting Topologies) neural networks.
7		*
8		* <p>Activations contains a collection of mathematical functions commonly used as activation functions
9		* in neural networks. These functions transform the weighted sum of inputs at each node into the node's
10		* output value, introducing non-linearity that enables neural networks to learn complex patterns.
11		*
12		* <p>Available activation functions:
13		* <ul>
14		* <li><strong>Linear</strong>: Simple linear transformation with slope and bias parameters</li>
15		* <li><strong>Sigmoid</strong>: Logistic function providing smooth transition between 0 and 1</li>
16		* <li><strong>Hyperbolic tangent</strong>: Smooth function providing output between -1 and 1</li>
17		* <li><strong>Identity</strong>: Pass-through function for linear networks</li>
18		* <li><strong>NEAT paper</strong>: Sigmoid variant with specific parameters from original NEAT research</li>
19		* </ul>
20		*
21		* <p>Function variations:
22		* <ul>
23		* <li><strong>Float versions</strong>: Optimized for float precision networks</li>
24		* <li><strong>Double versions</strong>: Higher precision for sensitive applications</li>
25		* <li><strong>Parameterized versions</strong>: Customizable function parameters</li>
26		* <li><strong>Pre-configured versions</strong>: Common parameter combinations</li>
27		* </ul>
28		*
29		* <p>Common usage patterns:
30		* <pre>{@code
31		* // Use standard sigmoid activation
32		* FeedForwardNetwork network = new FeedForwardNetwork(
33		* inputNodes, outputNodes, connections, Activations::sigmoid
34		* );
35		*
36		* // Custom sigmoid with different steepness
37		* Function<Double, Double> customSigmoid = Activations.sigmoid(2.0);
38		* FeedForwardNetwork steeperNetwork = new FeedForwardNetwork(
39		* inputNodes, outputNodes, connections, customSigmoid
40		* );
41		*
42		* // Hyperbolic tangent for outputs in [-1, 1] range
43		* FeedForwardNetwork tanhNetwork = new FeedForwardNetwork(
44		* inputNodes, outputNodes, connections, Activations::tanh
45		* );
46		*
47		* // Linear activation for regression problems
48		* FeedForwardNetwork linearNetwork = new FeedForwardNetwork(
49		* inputNodes, outputNodes, connections, Activations::identity
50		* );
51		*
52		* // Float versions for memory efficiency
53		* Function<Float, Float> floatSigmoid = Activations.sigmoidFloat;
54		* }</pre>
55		*
56		* <p>Activation function characteristics:
57		* <ul>
58		* <li><strong>Sigmoid</strong>: Smooth, bounded [0,1], good for binary classification</li>
59		* <li><strong>Tanh</strong>: Smooth, bounded [-1,1], zero-centered, often preferred over sigmoid</li>
60		* <li><strong>Linear</strong>: Unbounded, preserves gradients, suitable for regression</li>
61		* <li><strong>Identity</strong>: No transformation, useful for pass-through connections</li>
62		* </ul>
63		*
64		* <p>Performance considerations:
65		* <ul>
66		* <li><strong>Float vs Double</strong>: Float versions use less memory and may be faster</li>
67		* <li><strong>Function references</strong>: Pre-defined functions avoid object creation</li>
68		* <li><strong>Mathematical operations</strong>: Optimized implementations for common cases</li>
69		* <li><strong>Branch prediction</strong>: Simple functions improve CPU branch prediction</li>
70		* </ul>
71		*
72		* <p>Integration with NEAT evolution:
73		* <ul>
74		* <li><strong>Network evaluation</strong>: Applied to hidden and output nodes during forward propagation</li>
75		* <li><strong>Fitness computation</strong>: Affects network behavior and resulting fitness</li>
76		* <li><strong>Gradient flow</strong>: Function choice impacts learning and evolution dynamics</li>
77		* <li><strong>Problem matching</strong>: Different problems benefit from different activation functions</li>
78		* </ul>
79		*
80		* @see FeedForwardNetwork
81		* @see NeatChromosome
82		* @see Function
83		*/
84		public class Activations {
85
86		private Activations() {
87		}
88
89		/**
90		* Creates a linear activation function with specified slope and bias for float values.
91		*
92		* <p>The linear function computes: f(x) = a * x + b
93		*
94		* @param a the slope parameter
95		* @param b the bias parameter
96		* @return a linear activation function
97		*/
98		public static Function<Float, Float> linearFloat(final float a, final float b) {
99	6 1. lambda$linearFloat$0 : replaced Float return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$linearFloat$0 → KILLED 2. lambda$linearFloat$0 : Replaced float multiplication with division → KILLED 3. lambda$linearFloat$0 : removed call to java/lang/Float::floatValue → KILLED 4. lambda$linearFloat$0 : Replaced float addition with subtraction → KILLED 5. lambda$linearFloat$0 : removed call to java/lang/Float::valueOf → KILLED 6. linearFloat : replaced return value with null for net/bmahe/genetics4j/neat/Activations::linearFloat → KILLED	return (x) -> a * x + b;
100		}
101
102		/**
103		* Creates a linear activation function with specified slope and bias for double values.
104		*
105		* <p>The linear function computes: f(x) = a * x + b
106		*
107		* @param a the slope parameter
108		* @param b the bias parameter
109		* @return a linear activation function
110		*/
111		public static Function<Double, Double> linear(final double a, final double b) {
112	6 1. linear : replaced return value with null for net/bmahe/genetics4j/neat/Activations::linear → KILLED 2. lambda$linear$1 : removed call to java/lang/Double::doubleValue → KILLED 3. lambda$linear$1 : removed call to java/lang/Double::valueOf → KILLED 4. lambda$linear$1 : replaced Double return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$linear$1 → KILLED 5. lambda$linear$1 : Replaced double multiplication with division → KILLED 6. lambda$linear$1 : Replaced double addition with subtraction → KILLED	return (x) -> a * x + b;
113		}
114
115		/**
116		* Creates a sigmoid activation function with specified steepness for float values.
117		*
118		* <p>The sigmoid function computes: f(x) = 1 / (1 + exp(-a * x))
119		* <p>Output range: (0, 1)
120		*
121		* @param a the steepness parameter (higher values create steeper transitions)
122		* @return a sigmoid activation function
123		*/
124		public static Function<Float, Float> sigmoidFloat(final float a) {
125	12 1. lambda$sigmoidFloat$2 : Replaced float division with multiplication → KILLED 2. sigmoidFloat : replaced return value with null for net/bmahe/genetics4j/neat/Activations::sigmoidFloat → KILLED 3. lambda$sigmoidFloat$2 : removed call to java/lang/Float::valueOf → KILLED 4. lambda$sigmoidFloat$2 : removed call to java/lang/Math::exp → KILLED 5. lambda$sigmoidFloat$2 : Substituted 1.0 with 2.0 → KILLED 6. lambda$sigmoidFloat$2 : removed negation → KILLED 7. lambda$sigmoidFloat$2 : replaced call to java/lang/Math::exp with argument → KILLED 8. lambda$sigmoidFloat$2 : removed call to java/lang/Float::floatValue → KILLED 9. lambda$sigmoidFloat$2 : Replaced float multiplication with division → KILLED 10. lambda$sigmoidFloat$2 : Replaced float addition with subtraction → KILLED 11. lambda$sigmoidFloat$2 : replaced Float return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$sigmoidFloat$2 → KILLED 12. lambda$sigmoidFloat$2 : Substituted 1.0 with 2.0 → KILLED	return (x) -> 1.0f / (1.0f + (float) Math.exp(-a * x));
126		}
127
128		/**
129		* Creates a sigmoid activation function with specified steepness for double values.
130		*
131		* <p>The sigmoid function computes: f(x) = 1 / (1 + exp(-a * x))
132		* <p>Output range: (0, 1)
133		*
134		* @param a the steepness parameter (higher values create steeper transitions)
135		* @return a sigmoid activation function
136		*/
137		public static Function<Double, Double> sigmoid(final double a) {
138	12 1. lambda$sigmoid$3 : Replaced double division with multiplication → KILLED 2. lambda$sigmoid$3 : removed call to java/lang/Double::valueOf → KILLED 3. lambda$sigmoid$3 : Substituted 1.0 with 2.0 → KILLED 4. lambda$sigmoid$3 : replaced call to java/lang/Math::exp with argument → KILLED 5. lambda$sigmoid$3 : removed call to java/lang/Double::doubleValue → KILLED 6. lambda$sigmoid$3 : Replaced double addition with subtraction → KILLED 7. lambda$sigmoid$3 : removed call to java/lang/Math::exp → KILLED 8. sigmoid : replaced return value with null for net/bmahe/genetics4j/neat/Activations::sigmoid → KILLED 9. lambda$sigmoid$3 : Replaced double multiplication with division → KILLED 10. lambda$sigmoid$3 : removed negation → KILLED 11. lambda$sigmoid$3 : Substituted 1.0 with 2.0 → KILLED 12. lambda$sigmoid$3 : replaced Double return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$sigmoid$3 → KILLED	return (x) -> 1.0d / (1.0d + Math.exp(-a * x));
139		}
140
141		/** Standard sigmoid activation function for float values (steepness = 1.0). */
142		public static Function<Float, Float> sigmoidFloat = sigmoidFloat(1.0f);
143
144		/** Standard sigmoid activation function for double values (steepness = 1.0). */
145		public static Function<Double, Double> sigmoid = sigmoid(1.0d);
146
147		/** Identity activation function for float values (f(x) = x). */
148		public static Function<Float, Float> identityFloat = linearFloat(1.0f, 0.0f);
149
150		/** Identity activation function for double values (f(x) = x). */
151		public static Function<Double, Double> identity = linear(1.0d, 0.0d);
152
153		/** Hyperbolic tangent activation function for float values. Output range: (-1, 1). */
154	5 1. lambda$static$4 : replaced call to java/lang/Math::tanh with argument → KILLED 2. lambda$static$4 : removed call to java/lang/Math::tanh → KILLED 3. lambda$static$4 : removed call to java/lang/Float::valueOf → KILLED 4. lambda$static$4 : removed call to java/lang/Float::floatValue → KILLED 5. lambda$static$4 : replaced Float return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$static$4 → KILLED	public static Function<Float, Float> tanhFloat = (x) -> (float) Math.tanh(x);
155
156		/** Hyperbolic tangent activation function for double values. Output range: (-1, 1). */
157	5 1. lambda$static$5 : removed call to java/lang/Double::valueOf → KILLED 2. lambda$static$5 : removed call to java/lang/Double::doubleValue → KILLED 3. lambda$static$5 : removed call to java/lang/Math::tanh → KILLED 4. lambda$static$5 : replaced call to java/lang/Math::tanh with argument → KILLED 5. lambda$static$5 : replaced Double return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$static$5 → KILLED	public static Function<Double, Double> tanh = (x) -> Math.tanh(x);
158
159		/** Sigmoid activation function with steepness 4.9 as used in the original NEAT paper (float version). */
160		public static Function<Float, Float> neatPaperFloat = sigmoidFloat(4.9f);
161
162		/** Sigmoid activation function with steepness 4.9 as used in the original NEAT paper (double version). */
163		public static Function<Double, Double> neatPaper = sigmoid(4.9f);
164		}
		Mutations
99		1.1 Location : lambda$linearFloat$0 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] replaced Float return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$linearFloat$0 → KILLED 2.2 Location : lambda$linearFloat$0 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] Replaced float multiplication with division → KILLED 3.3 Location : lambda$linearFloat$0 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] removed call to java/lang/Float::floatValue → KILLED 4.4 Location : lambda$linearFloat$0 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyLinear()] Replaced float addition with subtraction → KILLED 5.5 Location : lambda$linearFloat$0 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] removed call to java/lang/Float::valueOf → KILLED 6.6 Location : linearFloat Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyLinear()] replaced return value with null for net/bmahe/genetics4j/neat/Activations::linearFloat → KILLED
112		1.1 Location : linear Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyLinear()] replaced return value with null for net/bmahe/genetics4j/neat/Activations::linear → KILLED 2.2 Location : lambda$linear$1 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] removed call to java/lang/Double::doubleValue → KILLED 3.3 Location : lambda$linear$1 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] removed call to java/lang/Double::valueOf → KILLED 4.4 Location : lambda$linear$1 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] replaced Double return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$linear$1 → KILLED 5.5 Location : lambda$linear$1 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyIdentity()] Replaced double multiplication with division → KILLED 6.6 Location : lambda$linear$1 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyLinear()] Replaced double addition with subtraction → KILLED
125		1.1 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Replaced float division with multiplication → KILLED 2.2 Location : sigmoidFloat Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNotNull()] replaced return value with null for net/bmahe/genetics4j/neat/Activations::sigmoidFloat → KILLED 3.3 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed call to java/lang/Float::valueOf → KILLED 4.4 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed call to java/lang/Math::exp → KILLED 5.5 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Substituted 1.0 with 2.0 → KILLED 6.6 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed negation → KILLED 7.7 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] replaced call to java/lang/Math::exp with argument → KILLED 8.8 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed call to java/lang/Float::floatValue → KILLED 9.9 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Replaced float multiplication with division → KILLED 10.10 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Replaced float addition with subtraction → KILLED 11.11 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] replaced Float return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$sigmoidFloat$2 → KILLED 12.12 Location : lambda$sigmoidFloat$2 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Substituted 1.0 with 2.0 → KILLED
138		1.1 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Replaced double division with multiplication → KILLED 2.2 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed call to java/lang/Double::valueOf → KILLED 3.3 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Substituted 1.0 with 2.0 → KILLED 4.4 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] replaced call to java/lang/Math::exp with argument → KILLED 5.5 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed call to java/lang/Double::doubleValue → KILLED 6.6 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Replaced double addition with subtraction → KILLED 7.7 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed call to java/lang/Math::exp → KILLED 8.8 Location : sigmoid Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNotNull()] replaced return value with null for net/bmahe/genetics4j/neat/Activations::sigmoid → KILLED 9.9 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Replaced double multiplication with division → KILLED 10.10 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] removed negation → KILLED 11.11 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] Substituted 1.0 with 2.0 → KILLED 12.12 Location : lambda$sigmoid$3 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyNeatSigmoid()] replaced Double return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$sigmoid$3 → KILLED
154		1.1 Location : lambda$static$4 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] replaced call to java/lang/Math::tanh with argument → KILLED 2.2 Location : lambda$static$4 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] removed call to java/lang/Math::tanh → KILLED 3.3 Location : lambda$static$4 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] removed call to java/lang/Float::valueOf → KILLED 4.4 Location : lambda$static$4 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] removed call to java/lang/Float::floatValue → KILLED 5.5 Location : lambda$static$4 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] replaced Float return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$static$4 → KILLED
157		1.1 Location : lambda$static$5 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] removed call to java/lang/Double::valueOf → KILLED 2.2 Location : lambda$static$5 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] removed call to java/lang/Double::doubleValue → KILLED 3.3 Location : lambda$static$5 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] removed call to java/lang/Math::tanh → KILLED 4.4 Location : lambda$static$5 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] replaced call to java/lang/Math::tanh with argument → KILLED 5.5 Location : lambda$static$5 Killed by : net.bmahe.genetics4j.neat.ActivationsTest.[engine:junit-jupiter]/[class:net.bmahe.genetics4j.neat.ActivationsTest]/[method:verifyTanh()] replaced Double return value with 0 for net/bmahe/genetics4j/neat/Activations::lambda$static$5 → KILLED

Activations.java

Mutations

Active mutators

Tests examined