niklas/ki_rwu_java
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Minor changes in names and extracted method, etc.

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This commit is contained in:
Niklas Birk
2021-11-30 22:27:45 +01:00
parent d0adbf0acb
commit 24c9e0b247
4 changed files with 26 additions and 22 deletions
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23
src/machine_learning/Vector.java
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@ -34,7 +34,7 @@ public class Vector
public Vector add(Vector b)
{
if (this.dimension() != b.dimension()) throw new IllegalArgumentException("Dimensions must be equals.");
checkEqualDimensions(b);
return new Vector(IntStream.range(0,
this.dimension())
.mapToObj(i -> this.get(i) + b.get(i))
@ -45,7 +45,7 @@ public class Vector
public Vector subtract(Vector b)
{
if (this.dimension() != b.dimension()) throw new IllegalArgumentException("Dimensions must be equals.");
checkEqualDimensions(b);
return new Vector(IntStream.range(0,
this.dimension())
.mapToObj(i -> this.get(i) - b.get(i))
@ -55,7 +55,7 @@ public class Vector
public double scalar(Vector b)
{
if (this.dimension() != b.dimension()) throw new IllegalArgumentException("Dimensions must be equals.");
checkEqualDimensions(b);
return IntStream.range(0,
this.dimension())
.mapToDouble(i -> this.get(i) * b.get(i))
@ -80,14 +80,9 @@ public class Vector
public Vector divide(double div)
{
var divided = new ArrayList<Double>();
for (int i = 0; i < this.dimension(); i++)
{
divided.add(this.values.get(i) / div);
}
return new Vector(divided);
return new Vector(IntStream.range(0, this.dimension())
.mapToObj(i -> this.values.get(i) / div)
.collect(Collectors.toCollection(ArrayList::new)));
}
public double get(int index)
@ -133,4 +128,10 @@ public class Vector
{
return this.values.toString();
}
private void checkEqualDimensions(Vector b)
{
if (this.dimension() != b.dimension())
throw new IllegalArgumentException("Dimensions must be equal");
}
}

2
src/machine_learning/nearest_neighbour/Distance.java → src/machine_learning/nearest_neighbour/DistanceFunction.java
View File

@ -2,7 +2,7 @@ package machine_learning.nearest_neighbour;
import machine_learning.Vector;
public interface Distance
public interface DistanceFunction
{
double distance(Vector a, Vector b);
}

12
src/machine_learning/nearest_neighbour/KNearestNeighbour.java
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@ -15,18 +15,18 @@ public class KNearestNeighbour implements MachineLearning
private List<Vector> positives;
private List<Vector> negatives;
private final Distance distance;
private final DistanceFunction distanceFunction;
private final int k;
public KNearestNeighbour(Distance distance)
public KNearestNeighbour(DistanceFunction distanceFunction)
{
this(distance, 1);
this(distanceFunction, 1);
}
public KNearestNeighbour(Distance distance, int k)
public KNearestNeighbour(DistanceFunction distanceFunction, int k)
{
this.distance = distance;
this.distanceFunction = distanceFunction;
this.k = k;
}
@ -67,7 +67,7 @@ public class KNearestNeighbour implements MachineLearning
private List<Vector> nearestNeighbours(List<Vector> vectors, Vector vector)
{
return vectors.parallelStream()
.map(v -> Map.entry(this.distance.distance(v, vector), v))
.map(v -> Map.entry(this.distanceFunction.distance(v, vector), v))
.sorted((e1, e2) -> e1.getKey() >= e2.getKey() ? (e1.getKey().equals(e2.getKey()) ? 0 : 1) : -1)
.map(Map.Entry::getValue)
.collect(Collectors.toList())