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MutableMatrix -- the class of all mutable matrices


A mutable matrix in Macaulay2 is a rectangular array of elements of a specific ring, whose entries can be modified.

A mutable matrix is different from a Matrix in that a matrix contains degree information for the target and source of the matrix, while a mutable matrix has no such information. Also, more operations are provided for matrices.

For an overview of mutable matrices, see mutable matrices.

Mutable matrices can either be encoded in a sparse manner (the matrix only encodes the non-zero elements), or in a dense manner (all elements are stored -- even zeros). The distinction is an option to several of the routines that create mutable matrices (mutableMatrix, mutableIdentity). Certain operations over RR or CC are performed using the lapack library and require dense encoding of matrices: LUdecomposition, SVD, solve, eigenvalues, eigenvectors.

row and column operations

matrix arithmetic

Many matrix arithmetic routines are only available for immutable matrices, not mutable matrices. It is necessary to use matrix to make an immutable matrix first.

Functions and methods returning a mutable matrix :

Methods that use a mutable matrix :

For the programmer

The object MutableMatrix is a type, with ancestor classes HashTable < Thing.