Package org.djunits.vecmat.def

Class SquareDenseMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

java.lang.Object

org.djunits.vecmat.def.VectorMatrix<Q,U,M,SI,H>

org.djunits.vecmat.def.Matrix<Q,U,M,SI,H>

org.djunits.vecmat.def.SquareMatrix<Q,U,M,SI,H>

org.djunits.vecmat.def.SquareDenseMatrix<Q,U,M,SI,H>

Type Parameters:

Q - the quantity type

U - the unit type

M - the 'SELF' square dense matrix type

SI - the square dense matrix type with generics <SIQuantity, SIUnit<

H - the generic square dense matrix type with generics <?, ?< for Hadamard operations

All Implemented Interfaces:

Serializable, Additive<M>, Scalable<M>, Value<U,M>, Hadamard<H,SI>

Direct Known Subclasses:

Matrix1x1, Matrix2x2, Matrix3x3

public abstract class SquareDenseMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>
extends SquareMatrix<Q,U,M,SI,H>

SquareDenseMatrix implements the core functions for a matrix with n x n real-valued entries. The data is stored in a dense double[] field. The matrix is immutable, except for the display unit, which can be changed.

Copyright (c) 2025-2026 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See for project information https://djunits.org. The DJUNITS project is distributed under a three-clause BSD-style license.

Author:

Alexander Verbraeck

See Also:

• Serialized Form

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SquareDenseMatrix(double[] dataInUnit, U displayUnit, int order)	Create a new SquareDenseMatrix with a unit.

Method Summary

Modifier and Type	Method	Description
int	cols()	Return the number of columns.
boolean	equals(Object obj)
double[]	getColumnSi(int col)	Return an array with SI-values for the given column (0-based) from the vector or matrix.
double[]	getRowSi(int row)	Return an array with SI-values for the given row (0-based) from the vector or matrix.
int	hashCode()
int	rows()	Return the number of rows.
double[]	si()	Return a row-major array of SI-values for this matrix or vector.
double	si(int row, int col)	Return the si-value at position (row, col), where both row and col are 0-based values.

Methods inherited from class org.djunits.vecmat.def.SquareMatrix

adjugate, determinant, determinantScalar, getDiagonalScalars, getDiagonalSi, getDiagonalVector, inverse, isSkewSymmetric, isSkewSymmetric, isSymmetric, isSymmetric, normFrobenius, order, trace, transpose

Methods inherited from class org.djunits.vecmat.def.Matrix

checkMultiply, checkMultiply, multiply

Methods inherited from class org.djunits.vecmat.def.VectorMatrix

abs, add, add, asMatrixNxM, asQuantityTable, checkCol, checkRow, divideElements, divideElements, get, getColumnScalars, getColumnVector, getDisplayUnit, getRowScalars, getRowVector, getScalarGrid, instantiateSi, instantiateSi, invertElements, isRelative, max, mcheckCol, mcheckRow, mean, median, mget, mgetColumnScalars, mgetColumnSi, mgetColumnVector, mgetRowScalars, mgetRowSi, mgetRowVector, min, mode, msi, multiplyElements, multiplyElements, multiplyElements, negate, scaleBy, setDisplayUnit, subtract, subtract, sum, toString, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.djunits.vecmat.operations.Hadamard

divideElements

Methods inherited from interface org.djunits.value.Scalable

divideBy

Methods inherited from interface org.djunits.value.Value

isAbsolute, setDisplayUnit

Constructor Details

SquareDenseMatrix

protected SquareDenseMatrix(double[] dataInUnit,
 U displayUnit,
 int order)

Create a new SquareDenseMatrix with a unit.

Parameters:

dataInUnit - the matrix values {a11, a12, ..., a21, a22, ...} expressed in the display unit

displayUnit - the display unit to use

order - the order of the square matrix (number of rows/columns)

Method Details

si

public double[] si()

Description copied from class: VectorMatrix

Return a row-major array of SI-values for this matrix or vector. Note that this is NOT a safe copy.

Specified by:

si in class VectorMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

Returns:

the row-major array of SI-values

si

public double si(int row,
 int col)

Description copied from class: VectorMatrix

Return the si-value at position (row, col), where both row and col are 0-based values.

Specified by:

si in class VectorMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

Parameters:

row - the row (0-based)

col - the column (0-based)

Returns:

the si-value at position (row, col)

rows

public int rows()

Description copied from class: VectorMatrix

Return the number of rows.

Specified by:

rows in class VectorMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

Returns:

the number of rows

cols

public int cols()

Description copied from class: VectorMatrix

Return the number of columns.

Specified by:

cols in class VectorMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

Returns:

the number of columns

getRowSi

public double[] getRowSi(int row)

Description copied from class: VectorMatrix

Return an array with SI-values for the given row (0-based) from the vector or matrix.

Specified by:

getRowSi in class VectorMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

Parameters:

row - the row number to retrieve (0-based)

Returns:

an array with SI-values with the data at the given row

getColumnSi

public double[] getColumnSi(int col)

Description copied from class: VectorMatrix

Return an array with SI-values for the given column (0-based) from the vector or matrix.

Specified by:

getColumnSi in class VectorMatrix<Q extends Quantity<Q,U>,U extends UnitInterface<U,Q>,M extends SquareDenseMatrix<Q,U,M,SI,H>,SI extends SquareDenseMatrix<SIQuantity,SIUnit,SI,?,?>,H extends SquareDenseMatrix<?,?,?,?,?>>

Parameters:

col - the column number to retrieve (0-based)

Returns:

an array with SI-values with the data at the given column

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object