Package org.djunits.vecmat.def

Class AbsSquareMatrix<A extends AbsQuantity<A,Q,?>,Q extends Quantity<Q>,MA extends AbsSquareMatrix<A,Q,MA,MQ>,MQ extends SquareMatrix<Q,MQ,?,?>>

java.lang.Object

org.djunits.vecmat.def.AbsVectorMatrix<A,Q,MA,MQ,MAT>

org.djunits.vecmat.def.AbsTable<A,Q,MA,MQ,MAT>

org.djunits.vecmat.def.AbsMatrix<A,Q,MA,MQ,MA>

org.djunits.vecmat.def.AbsSquareMatrix<A,Q,MA,MQ>

Type Parameters:

A - the absolute quantity type

Q - the quantity type

MA - the absolute matrix type

MQ - the relative matrix type

All Implemented Interfaces:

Serializable, Value<MA,Q>

Direct Known Subclasses:

AbsMatrix1x1, AbsMatrix2x2, AbsMatrix3x3, AbsMatrixNxN

public abstract class AbsSquareMatrix<A extends AbsQuantity<A,Q,?>,Q extends Quantity<Q>,MA extends AbsSquareMatrix<A,Q,MA,MQ>,MQ extends SquareMatrix<Q,MQ,?,?>>
extends AbsMatrix<A,Q,MA,MQ,MA>

AbsSquareMatrix defines a number of operations that can be applied to square matrixes with absolute quantity values.

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

Constructor	Description
AbsSquareMatrix(MQ matrix, Reference<?,A,Q> reference)	Create a new square matrix of absolute values with a reference point.

Method Summary

Modifier and Type	Method	Description
A[]	getDiagonalScalars()	Retrieve the main diagonal of the matrix as an array of scalars.
double[]	getDiagonalSi()	Retrieve the main diagonal of the matrix as an array of doubles with SI-values.
abstract AbsVector<A,Q,?,?,?>	getDiagonalVector()	Retrieve the main diagonal of the matrix as a column vector.
boolean	isSkewSymmetric()	Return whether the matrix is skew symmetric.
boolean	isSkewSymmetric(Q tolerance)	Return whether the matrix is skew symmetric, up to a tolerance.
boolean	isSymmetric()	Return whether the matrix is symmetric.
boolean	isSymmetric(Q tolerance)	Return whether the matrix is symmetric, up to a tolerance.
int	order()	Return the order (the number of rows/columns) of this matrix.
MA	transpose()	Return a transposed absolute vector or matrix, where rows and columns have been swapped.

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

format, format, format

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

get, getColumnScalars, getColumnSi, getColumnVector, getRowScalars, getRowSi, getRowVector, getScalarArray, getScalarGrid, getSiArray, getSiGrid, mget, mgetColumnScalars, mgetColumnSi, mgetColumnVector, mgetRowScalars, mgetRowSi, mgetRowVector, msi, si

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

add, add, asAbsMatrix1x1, asAbsMatrix2x2, asAbsMatrix3x3, asAbsMatrixNxM, asAbsMatrixNxN, asAbsQuantityTable, asAbsVector1, asAbsVector2Col, asAbsVector2Row, asAbsVector3Col, asAbsVector3Row, asAbsVectorNCol, asAbsVectorNRow, checkCol, checkRow, cols, equals, getDisplayUnit, getReference, getRelativeVecMat, hashCode, instantiate, instantiateSi, isRelative, max, mcheckCol, mcheckRow, median, min, rows, setDisplayUnit, subtract, subtract, subtract, subtract, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.djunits.value.Value

isAbsolute, setDisplayUnit

Constructor Details

AbsSquareMatrix

public AbsSquareMatrix(MQ matrix,
 Reference<?,A,Q> reference)

Create a new square matrix of absolute values with a reference point.

Parameters:

matrix - the underlying relative square matrix with SI values relative to the reference point

reference - the reference point for the absolute values

Method Details

order

public int order()

Return the order (the number of rows/columns) of this matrix.

Returns:

the order (the number of rows/columns) of this matrix

transpose

public MA transpose()

Description copied from class: AbsVectorMatrix

Return a transposed absolute vector or matrix, where rows and columns have been swapped.

Specified by:

transpose in class AbsVectorMatrix<A extends AbsQuantity<A,Q,?>,Q extends Quantity<Q>,MA extends AbsSquareMatrix<A,Q,MA,MQ>,MQ extends SquareMatrix<Q,MQ,?,?>,MA extends AbsSquareMatrix<A,Q,MA,MQ>>

Returns:

a transposed absolute vector or matrix, where rows and columns have been swapped

getDiagonalVector

public abstract AbsVector<A,Q,?,?,?> getDiagonalVector()

Retrieve the main diagonal of the matrix as a column vector.

Returns:

the main diagonal as a Vector

getDiagonalScalars

public A[] getDiagonalScalars()

Retrieve the main diagonal of the matrix as an array of scalars.

Returns:

the main diagonal as a Scalar array

getDiagonalSi

public double[] getDiagonalSi()

Retrieve the main diagonal of the matrix as an array of doubles with SI-values.

Returns:

the main diagonal as a doube array with SI-values

isSymmetric

public boolean isSymmetric()

Return whether the matrix is symmetric. Use a public tolerance of 1.0E-12 times the largest absolute si quantity.

Returns:

whether the matrix is symmetric

isSymmetric

public boolean isSymmetric(Q tolerance)

Return whether the matrix is symmetric, up to a tolerance.

Parameters:

tolerance - the tolerance, expressed as a quantity

Returns:

whether the matrix is symmetric

isSkewSymmetric

public boolean isSkewSymmetric()

Return whether the matrix is skew symmetric. Use a public tolerance of 1.0E-12 times the largest absolute si quantity.

Returns:

whether the matrix is skew symmetric

isSkewSymmetric

public boolean isSkewSymmetric(Q tolerance)

Return whether the matrix is skew symmetric, up to a tolerance.

Parameters:

tolerance - the tolerance, expressed as a quantity

Returns:

whether the matrix is skew symmetric