0.3.4

core/gay.zharel.hermes.math/Matrix

Matrix

class Matrix

Represents a matrix of doubles. Internally represented as a SimpleMatrix from EJML.

Constructors

constructor(data: Array<DoubleArray>)

Constructor to create a Matrix from a 2D array.

constructor(data: Collection<Collection<Double>>)

Constructor to create a Matrix from a list of lists.

Types

object Companion

Properties

@get:JvmName(name = "inverse")

val inverse: Matrix

The inverse of this matrix. The matrix must be square and invertible. If the matrix is not square, use pseudoInverse instead.

@get:JvmName(name = "norm")

val norm: Double

Returns the Frobenius norm of this matrix. The Frobenius norm is the square root of the sum of squares of all elements.

val numColumns: Int

The number of columns in the matrix.

val numRows: Int

The number of rows in the matrix.

@get:JvmName(name = "pseudoInverse")

val pseudoInverse: Matrix

The pseudo-inverse of this matrix. The matrix must be square and invertible.

val size: Pair<Int, Int>

The size of the matrix.

@get:JvmName(name = "transpose")

val transpose: Matrix

The transpose of this matrix.

Functions

fun column(n: Int): Matrix

Returns the nth column of the matrix.

fun copy(): Matrix

Returns a copy of this matrix.

fun diagonals(): Matrix

Returns the diagonal elements of this matrix.

open operator override fun equals(other: Any?): Boolean

operator fun get(i: Int, j: Int): Double

Returns the element at the given indices.

open override fun hashCode(): Int

fun ldlt(): LDLTDecomposition

Returns the LDLT decomposition of this matrix. Only works for symmetric matrices.

fun llt(): LLTDecomposition

Returns the LLT (Cholesky) decomposition of this matrix. Only works for symmetric, positive-definite matrices. Provides in-place rank-1 update/downdate methods.

fun lu(): LUDecomposition

Returns the LU decomposition of this matrix.

operator fun minus(other: Matrix): Matrix

Subtracts another matrix from this matrix. The matrices must have the same dimensions.

operator fun plus(other: Matrix): Matrix

Adds another matrix to this matrix. The matrices must have the same dimensions.

fun qr(): QRDecomposition

Returns the QR decomposition of this matrix.

fun row(n: Int): Matrix

Returns the nth row of the matrix.

operator fun set(i: Int, j: Int, value: Double)

Sets the element at the given indices to the given value.

fun slice(startRow: Int, endRow: Int, startCol: Int, endCol: Int): Matrix

Returns a submatrix of this matrix.

fun solve(other: Matrix): Matrix

operator fun times(other: Matrix): Matrix

Multiplies this matrix by another matrix. The number of columns in this matrix must match the number of rows in the other matrix.

operator fun times(scalar: Double): Matrix

operator fun times(scalar: Int): Matrix

Multiplies this matrix by a scalar.

open override fun toString(): String

operator fun unaryMinus(): Matrix

Returns the matrix with all elements negated. This is equivalent to multiplying the matrix by -1.