ILMathdistL2sq Method (InArrayDouble, InArrayDouble)

ILNumerics Ultimate VS Documentation

ILNumerics - Technical Application Development

Computes the [m x n] squared pairwise L2 distances between data points provided in A [d x m] and B [d x n].

[ILNumerics Computing Engine]

Namespace: ILNumerics
Assembly: ILNumerics.Computing (in ILNumerics.Computing.dll) Version: 5.5.0.0 (5.5.7503.3146)

Syntax

Copy

public static RetArray<double> distL2sq(
	InArray<double> A,
	InArray<double> B
)

Public Shared Function distL2sq ( 
	A As InArray(Of Double),
	B As InArray(Of Double)
) As RetArray(Of Double)

Dim A As InArray(Of Double)
Dim B As InArray(Of Double)
Dim returnValue As RetArray(Of Double)

returnValue = ILMath.distL2sq(A, B)

Parameters

A: Type: ILNumericsInArrayDouble
Input data matrix A [d x m], m points are provided as columns of length d.
B: Type: ILNumericsInArrayDouble
Input data matrix B [d x n], n points are provided as columns of length d.

Return Value

Type: RetArrayDouble
Distance matrix D of size [m x n]. D_i,j is the squared euclidian distance between data point i in A and data point j in B.

Remarks

This function computes the square of the pairwise euclidian (L2) distances between data values in A and B.

In order to get the non-squared distances one may use the sqrt(BaseArrayDouble) function on the array returned.

For those coming from languages like Matlab / Octave: the equivalent function there would be: bsxfun(@plus, dot(X, X, 1)',dot(Y,Y,1))-2*(X' * Y)

[ILNumerics Computing Engine]

Reference

ILMath Class

distL2sq Overload

ILNumerics Namespace