Class EJMLBackend<E>

java.lang.Object

org.episteme.core.mathematics.linearalgebra.backends.EJMLBackend<E>

All Implemented Interfaces:

AutoCloseable, LinearAlgebraProvider<E>, AlgorithmProvider, Backend, ComputeBackend, CPUBackend

@AutoService({Backend.class,CPUBackend.class,LinearAlgebraProvider.class})
public class EJMLBackend<E>
extends Object
implements CPUBackend, LinearAlgebraProvider<E>

CPU compute backend for EJML (Efficient Java Matrix Library).

EJML is a high-performance, pure Java linear algebra library focused on dense matrices. This backend wraps the EJML linear algebra provider and integrates it into the Episteme backend discovery system.

Since:

1.0

Author:

Silvere Martin-Michiellot, Gemini AI (Google DeepMind)

Constructor Summary

Constructors

Constructor	Description
EJMLBackend()
EJMLBackend(Field<E> field)

Method Summary

Modifier and Type	Method	Description
Matrix<E>	acos(Matrix<E> a)
Matrix<E>	acosh(Matrix<E> a)
Matrix<E>	add(Matrix<E> a, Matrix<E> b)
Vector<E>	add(Vector<E> a, Vector<E> b)
E	angle(Vector<E> a, Vector<E> b)	Returns the angle between two vectors in radians.
Matrix<E>	asin(Matrix<E> a)
Matrix<E>	asinh(Matrix<E> a)
Matrix<E>	atan(Matrix<E> a)
Matrix<E>	atanh(Matrix<E> a)
Matrix<E>	cbrt(Matrix<E> a)
CholeskyResult<E>	cholesky(Matrix<E> a)	Computes the Cholesky decomposition of the specified matrix.
Matrix<E>	cos(Matrix<E> a)
Matrix<E>	cosh(Matrix<E> a)
Object	createBackend()	Creates and returns the backend instance (or returns self if it is the backend).
ExecutionContext	createContext()	Creates an execution context for running operations.
Vector<E>	cross(Vector<E> a, Vector<E> b)	Returns the cross product of two 3D vectors.
E	determinant(Matrix<E> a)
E	dot(Vector<E> a, Vector<E> b)
EigenResult<E>	eigen(Matrix<E> a)	Computes the eigenvalue decomposition of the specified matrix.
Matrix<E>	exp(Matrix<E> a)	Computes the matrix exponential e^A.
String	getDescription()	Returns a description of the backend.
String	getId()	Returns the unique identifier for this backend (e.g., "javafx", "jmol", "cuda").
String	getName()	Returns the display name for UI presentation.
int	getPriority()	Returns the priority for auto-selection (higher = preferred).
String	getType()	Returns the backend type category (e.g., "plotting", "molecular", "tensor", "math").
Matrix<E>	inverse(Matrix<E> a)
boolean	isAvailable()	Checks if this backend is currently available (libraries loaded, etc.).
boolean	isCompatible(Ring<?> ring)	Checks if this provider is compatible with the given ring.
Matrix<E>	log(Matrix<E> a)
Matrix<E>	log10(Matrix<E> a)
LUResult<E>	lu(Matrix<E> a)	Computes the LU decomposition of the specified matrix.
Matrix<E>	multiply(Matrix<E> a, Matrix<E> b)
Vector<E>	multiply(Matrix<E> a, Vector<E> b)
Vector<E>	multiply(Vector<E> v, E s)
E	norm(Vector<E> a)
Vector<E>	normalize(Vector<E> v)	Returns the normalized vector (unit vector).
Matrix<E>	pow(Matrix<E> a, E exponent)
Vector<E>	projection(Vector<E> a, Vector<E> b)	Returns the projection of vector a onto vector b.
QRResult<E>	qr(Matrix<E> a)	Computes the QR decomposition of the specified matrix.
Matrix<E>	scale(E s, Matrix<E> a)
double	score(OperationContext context)	Scores this provider for a specific operation context.
void	shutdown()	Called when the application is shutting down or the backend is being replaced.
Matrix<E>	sin(Matrix<E> a)
Matrix<E>	sinh(Matrix<E> a)
Vector<E>	solve(Matrix<E> a, Vector<E> b)
Vector<E>	solveTriangular(Matrix<E> A, Vector<E> b, boolean upper, boolean transpose, boolean conjugate, boolean unit)	Solves the triangular system Ax = b.
Matrix<E>	sqrt(Matrix<E> a)
Matrix<E>	subtract(Matrix<E> a, Matrix<E> b)
Vector<E>	subtract(Vector<E> a, Vector<E> b)
SVDResult<E>	svd(Matrix<E> a)	Computes the Singular Value Decomposition (SVD) of the specified matrix.
Matrix<E>	tan(Matrix<E> a)
Matrix<E>	tanh(Matrix<E> a)
E	trace(Matrix<E> a)
Matrix<E>	transpose(Matrix<E> a)

Methods inherited from class Object

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

Methods inherited from interface AlgorithmProvider

description, getMetadata

Methods inherited from interface Backend

getAlgorithmProviders, getStatusMessage, isExplicitlyDisabled

Methods inherited from interface CPUBackend

getAcceleratorType, supportsComplexNumbers, supportsFloatingPoint, supportsParallelOps

Methods inherited from interface LinearAlgebraProvider

close, conditionNumber, configure, conjugateTranspose, getAlgorithmType, getEnvironmentInfo, rank, solve, solve, solve

Constructor Details

EJMLBackend

public EJMLBackend()

EJMLBackend

public EJMLBackend(Field<E> field)

Method Details

getType

public String getType()

Description copied from interface: Backend

Returns the backend type category (e.g., "plotting", "molecular", "tensor", "math").

Specified by:

getType in interface Backend

Specified by:

getType in interface ComputeBackend

Specified by:

getType in interface CPUBackend

getId

public String getId()

Description copied from interface: Backend

Returns the unique identifier for this backend (e.g., "javafx", "jmol", "cuda").

Specified by:

getId in interface Backend

Specified by:

getId in interface ComputeBackend

getName

public String getName()

Description copied from interface: Backend

Returns the display name for UI presentation.

Specified by:

getName in interface AlgorithmProvider

Specified by:

getName in interface Backend

Specified by:

getName in interface LinearAlgebraProvider<E>

getDescription

public String getDescription()

Description copied from interface: Backend

Returns a description of the backend.

Specified by:

getDescription in interface Backend

Specified by:

getDescription in interface ComputeBackend

isAvailable

public boolean isAvailable()

Description copied from interface: Backend

Checks if this backend is currently available (libraries loaded, etc.).

Default implementation checks Backend.isExplicitlyDisabled() and returns false if it is.

Specified by:

isAvailable in interface AlgorithmProvider

Specified by:

isAvailable in interface Backend

getPriority

public int getPriority()

Description copied from interface: Backend

Returns the priority for auto-selection (higher = preferred). Used when multiple backends are available.

Specified by:

getPriority in interface AlgorithmProvider

Specified by:

getPriority in interface Backend

Specified by:

getPriority in interface LinearAlgebraProvider<E>

score

public double score(OperationContext context)

Description copied from interface: AlgorithmProvider

Scores this provider for a specific operation context.

Higher scores indicate better suitability. Used by ProviderSelector for context-aware selection.

Default implementation returns AlgorithmProvider.getPriority(), so existing providers behave identically without changes.

Specified by:

score in interface AlgorithmProvider

Specified by:

score in interface LinearAlgebraProvider<E>

Parameters:

context - the operation context (data size, hints, etc.)

Returns:

suitability score (higher = better)

createContext

public ExecutionContext createContext()

Description copied from interface: ComputeBackend

Creates an execution context for running operations.

The context should be used within a try-with-resources block to ensure proper cleanup of resources.

Specified by:

createContext in interface ComputeBackend

Returns:

new execution context

createBackend

public Object createBackend()

Description copied from interface: Backend

Creates and returns the backend instance (or returns self if it is the backend).

Specified by:

createBackend in interface Backend

Specified by:

createBackend in interface ComputeBackend

Returns:

The backend implementation object

shutdown

public void shutdown()

Description copied from interface: Backend

Called when the application is shutting down or the backend is being replaced. Use this to release hardware resources, close file handles, or stop background threads.

Specified by:

shutdown in interface AlgorithmProvider

Specified by:

shutdown in interface Backend

isCompatible

public boolean isCompatible(Ring<?> ring)

Description copied from interface: LinearAlgebraProvider

Checks if this provider is compatible with the given ring.

Specified by:

isCompatible in interface LinearAlgebraProvider<E>

add

public Vector<E> add(Vector<E> a,
 Vector<E> b)

Specified by:

add in interface LinearAlgebraProvider<E>

subtract

public Vector<E> subtract(Vector<E> a,
 Vector<E> b)

Specified by:

subtract in interface LinearAlgebraProvider<E>

multiply

public Vector<E> multiply(Vector<E> v,
 E s)

Specified by:

multiply in interface LinearAlgebraProvider<E>

dot

public E dot(Vector<E> a,
 Vector<E> b)

Specified by:

dot in interface LinearAlgebraProvider<E>

add

public Matrix<E> add(Matrix<E> a,
 Matrix<E> b)

Specified by:

add in interface LinearAlgebraProvider<E>

subtract

public Matrix<E> subtract(Matrix<E> a,
 Matrix<E> b)

Specified by:

subtract in interface LinearAlgebraProvider<E>

multiply

public Matrix<E> multiply(Matrix<E> a,
 Matrix<E> b)

Specified by:

multiply in interface LinearAlgebraProvider<E>

multiply

public Vector<E> multiply(Matrix<E> a,
 Vector<E> b)

Specified by:

multiply in interface LinearAlgebraProvider<E>

inverse

public Matrix<E> inverse(Matrix<E> a)

Specified by:

inverse in interface LinearAlgebraProvider<E>

determinant

public E determinant(Matrix<E> a)

Specified by:

determinant in interface LinearAlgebraProvider<E>

solve

public Vector<E> solve(Matrix<E> a,
 Vector<E> b)

Specified by:

solve in interface LinearAlgebraProvider<E>

transpose

public Matrix<E> transpose(Matrix<E> a)

Specified by:

transpose in interface LinearAlgebraProvider<E>

scale

public Matrix<E> scale(E s,
 Matrix<E> a)

Specified by:

scale in interface LinearAlgebraProvider<E>

norm

public E norm(Vector<E> a)

Specified by:

norm in interface LinearAlgebraProvider<E>

angle

public E angle(Vector<E> a,
 Vector<E> b)

Description copied from interface: LinearAlgebraProvider

Returns the angle between two vectors in radians.

Specified by:

angle in interface LinearAlgebraProvider<E>

qr

public QRResult<E> qr(Matrix<E> a)

Description copied from interface: LinearAlgebraProvider

Computes the QR decomposition of the specified matrix.

Specified by:

qr in interface LinearAlgebraProvider<E>

svd

public SVDResult<E> svd(Matrix<E> a)

Description copied from interface: LinearAlgebraProvider

Computes the Singular Value Decomposition (SVD) of the specified matrix.

Specified by:

svd in interface LinearAlgebraProvider<E>

eigen

public EigenResult<E> eigen(Matrix<E> a)

Description copied from interface: LinearAlgebraProvider

Computes the eigenvalue decomposition of the specified matrix.

Specified by:

eigen in interface LinearAlgebraProvider<E>

lu

public LUResult<E> lu(Matrix<E> a)

Description copied from interface: LinearAlgebraProvider

Computes the LU decomposition of the specified matrix.

Specified by:

lu in interface LinearAlgebraProvider<E>

cholesky

public CholeskyResult<E> cholesky(Matrix<E> a)

Description copied from interface: LinearAlgebraProvider

Computes the Cholesky decomposition of the specified matrix.

Specified by:

cholesky in interface LinearAlgebraProvider<E>

trace

public E trace(Matrix<E> a)

Specified by:

trace in interface LinearAlgebraProvider<E>

exp

public Matrix<E> exp(Matrix<E> a)

Description copied from interface: LinearAlgebraProvider

Computes the matrix exponential e^A.

Specified by:

exp in interface LinearAlgebraProvider<E>

log

public Matrix<E> log(Matrix<E> a)

Specified by:

log in interface LinearAlgebraProvider<E>

log10

public Matrix<E> log10(Matrix<E> a)

Specified by:

log10 in interface LinearAlgebraProvider<E>

sin

public Matrix<E> sin(Matrix<E> a)

Specified by:

sin in interface LinearAlgebraProvider<E>

cos

public Matrix<E> cos(Matrix<E> a)

Specified by:

cos in interface LinearAlgebraProvider<E>

tan

public Matrix<E> tan(Matrix<E> a)

Specified by:

tan in interface LinearAlgebraProvider<E>

asin

public Matrix<E> asin(Matrix<E> a)

Specified by:

asin in interface LinearAlgebraProvider<E>

acos

public Matrix<E> acos(Matrix<E> a)

Specified by:

acos in interface LinearAlgebraProvider<E>

atan

public Matrix<E> atan(Matrix<E> a)

Specified by:

atan in interface LinearAlgebraProvider<E>

sinh

public Matrix<E> sinh(Matrix<E> a)

Specified by:

sinh in interface LinearAlgebraProvider<E>

cosh

public Matrix<E> cosh(Matrix<E> a)

Specified by:

cosh in interface LinearAlgebraProvider<E>

tanh

public Matrix<E> tanh(Matrix<E> a)

Specified by:

tanh in interface LinearAlgebraProvider<E>

asinh

public Matrix<E> asinh(Matrix<E> a)

Specified by:

asinh in interface LinearAlgebraProvider<E>

acosh

public Matrix<E> acosh(Matrix<E> a)

Specified by:

acosh in interface LinearAlgebraProvider<E>

atanh

public Matrix<E> atanh(Matrix<E> a)

Specified by:

atanh in interface LinearAlgebraProvider<E>

sqrt

public Matrix<E> sqrt(Matrix<E> a)

Specified by:

sqrt in interface LinearAlgebraProvider<E>

cbrt

public Matrix<E> cbrt(Matrix<E> a)

Specified by:

cbrt in interface LinearAlgebraProvider<E>

pow

public Matrix<E> pow(Matrix<E> a,
 E exponent)

Specified by:

pow in interface LinearAlgebraProvider<E>

normalize

public Vector<E> normalize(Vector<E> v)

Description copied from interface: LinearAlgebraProvider

Returns the normalized vector (unit vector).

Specified by:

normalize in interface LinearAlgebraProvider<E>

cross

public Vector<E> cross(Vector<E> a,
 Vector<E> b)

Description copied from interface: LinearAlgebraProvider

Returns the cross product of two 3D vectors.

Specified by:

cross in interface LinearAlgebraProvider<E>

projection

public Vector<E> projection(Vector<E> a,
 Vector<E> b)

Description copied from interface: LinearAlgebraProvider

Returns the projection of vector a onto vector b.

Specified by:

projection in interface LinearAlgebraProvider<E>

solveTriangular

public Vector<E> solveTriangular(Matrix<E> A,
 Vector<E> b,
 boolean upper,
 boolean transpose,
 boolean conjugate,
 boolean unit)

Description copied from interface: LinearAlgebraProvider

Solves the triangular system Ax = b.

Specified by:

solveTriangular in interface LinearAlgebraProvider<E>

Parameters:

A - the triangular matrix

b - the right-hand side vector

upper - true if A is upper triangular, false if lower

transpose - true if solving A^T x = b

conjugate - true if solving A^H x = b (only if transpose is true and complex)

unit - true if A is unit triangular (diagonal is all ones)