NextControl Linear Algebra/dev.nextftc.linalg/Matrix

Matrix

open class Matrix<R : Nat, C : Nat>(source)

A dimensionally type-safe matrix of doubles.

The dimensions R (rows) and C (columns) are encoded at the type level using Nat types, allowing the compiler to catch dimension mismatches at compile time.

Example:

val a: Matrix<N2, N3> = Matrix.zero(N2, N3)  // 2x3 matrix
val b: Matrix<N3, N4> = Matrix.zero(N3, N4)  // 3x4 matrix
val c: Matrix<N2, N4> = a * b                      // 2x4 matrix - compiles!
// val d = a * a  // Would not compile - N3 != N2

Type Parameters

R

The row dimension type

C

The column dimension type

Inheritors

Constructors

constructor(data: Array<DoubleArray>)

Types

object Companion

Properties

@get:JvmName(name = "inverse")

val inverse: Matrix<R, C>

The inverse of this matrix. Only valid for square matrices.

val natColumns: C

Natural number representing the number of columns.

Natural number representing the number of rows.

@get:JvmName(name = "norm")

val norm: Double

The Frobenius norm of this matrix.

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<C, R>

The pseudo-inverse of this matrix.

val size: Pair<Int, Int>

The size of the matrix as (rows, columns).

@get:JvmName(name = "transpose")

val transpose: Matrix<C, R>

The transpose of this matrix, with swapped dimension types.

Functions

open fun copy(): Matrix<R, C>

Returns a copy of this matrix.

open operator fun div(scalar: Double): Matrix<R, C>

open operator fun div(scalar: Number): Matrix<R, C>

Divides this matrix by a scalar.

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

fun <N : Nat> Matrix<N, N>.exp(): Matrix<N, N>

Computes the matrix exponential of this matrix, using the Padé approximant.

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

Returns the element at the given indices.

open override fun hashCode(): Int

operator fun minus(other: Matrix<R, C>): Matrix<R, C>

Subtracts another matrix with the same dimensions.

operator fun plus(other: Matrix<R, C>): Matrix<R, C>

Adds another matrix with the same dimensions.

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

Sets the element at the given indices.

fun <K : Nat> solve(other: Matrix<R, K>): Matrix<C, K>

Solves for X in the equation AX = B, where A is this matrix and B is other.

operator fun <K : Nat> times(other: Matrix<C, K>): Matrix<R, K>

Multiplies this matrix by another matrix. The inner dimensions must match: (R x C) * (C x K) = (R x K)

operator fun times(other: Vector<C>): Vector<R>

Multiplies this matrix by a vector. The vector's length must be equal to C.

open operator fun times(scalar: Double): Matrix<R, C>

open operator fun times(scalar: Number): Matrix<R, C>

Multiplies this matrix by a scalar.

toDynamicMatrix

fun toDynamicMatrix(): DynamicMatrix

Converts to a DynamicMatrix.

open override fun toString(): String

open operator fun unaryMinus(): Matrix<R, C>

Negates all elements of this matrix.