Class EuclideanDistance

java.lang.Object

smile.math.distance.EuclideanDistance

All Implemented Interfaces:

Serializable, ToDoubleBiFunction<double[],double[]>, Distance<double[]>, Metric<double[]>

public class EuclideanDistance
extends Object
implements Metric<double[]>

Euclidean distance. For float or double arrays, missing values (i.e. NaN) are also handled.

See Also:

• SparseEuclideanDistance
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
EuclideanDistance()	Constructor.
EuclideanDistance(double[] weight)	Constructor with a given weight vector.

Method Summary

Modifier and Type	Method	Description
double	d(double[] x, double[] y)	Euclidean distance between the two arrays of type double.
double	d(float[] x, float[] y)	Euclidean distance between the two arrays of type float.
double	d(int[] x, int[] y)	Euclidean distance between the two arrays of type integer.
String	toString()

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface Distance

apply, applyAsDouble, pdist, pdist

Constructor Details

EuclideanDistance

public EuclideanDistance()

Constructor. Standard (unweighted) Euclidean distance.

EuclideanDistance

public EuclideanDistance(double[] weight)

Constructor with a given weight vector.

Parameters:

weight - the weight vector.

Method Details

toString

public String toString()

Overrides:

toString in class Object

d

public double d(int[] x,
 int[] y)

Euclidean distance between the two arrays of type integer. No missing value handling in this method.

Parameters:

x - a vector.

y - a vector.

Returns:

the distance.

d

public double d(float[] x,
 float[] y)

Euclidean distance between the two arrays of type float. NaN will be treated as missing values and will be excluded from the calculation. Let m be the number nonmissing values, and n be the number of all values. The returned distance is sqrt(n * d / m), where d is the square of distance between nonmissing values.

Parameters:

x - a vector.

y - a vector.

Returns:

the distance.

d

public double d(double[] x,
 double[] y)

Euclidean distance between the two arrays of type double. NaN will be treated as missing values and will be excluded from the calculation. Let m be the number nonmissing values, and n be the number of all values. The returned distance is sqrt(n * d / m), where d is the square of distance between nonmissing values.

Specified by:

d in interface Distance<double[]>

Parameters:

x - an object.

y - an object.

Returns:

the distance.