Definition of a Module#
Construction of Modules of \(n\)-tuples#
- RSpace(R, n): Rng, RngIntElt -> ModTupRng#
- RModule(R, n): Rng, RngIntElt -> ModRng#
Given a ring \(R\) and a non-negative integer \(n\), create the free right \(R\)-module \(R^{(n)}\), consisting of all \(n\)-tuples over \(R\). The module is created with the standard basis, \(e_1, \ldots, e_n\), where \(e_i\) \((i = 1, \ldots, n)\) is the vector containing a \(1\) in the \(i\)-th position and zeros elsewhere. The function
RModulecreates a module in reduced mode whileRSpacecreates a module in embedded mode.
- RSpace(R, n, F): Rng, RngIntElt, Mtrx -> ModTupRng#
Given a ring \(R\), a non-negative integer \(n\) and a square \(n \times n\) symmetric matrix \(F\), create the free right \(R\)-module \(R^{(n)}\) (in embedded form), with inner product matrix \(F\). This is the same as
RSpace(R, n), except that the functionsNormandInnerProduct(see below) will be with respect to the inner product matrix \(F\).
- Example: Create Z6 (ex-d42492)#
We construct the module consisting of \(6\)-tuples over the integers.
> Z := IntegerRing(); > M := RModule(Z, 6); > M; RModule M of dimension 6 with base ring Integer Ring
Construction of Modules of \(m \times n\) Matrices#
- RMatrixSpace(R, m, n): Rng, RngIntElt, RngIntElt -> ModMatRng#
The module comprising all \(m \times n\) matrices over the ring \(R\).
Construction of a Module with Specified Basis#
- RModuleWithBasis(Q): [ModFldElt] -> ModFld#
- RSpaceWithBasis(Q): [ModTupRngElt] -> ModTupRng#
- RSpaceWithBasis(a): AlgMatElt -> ModTupRng#
- RSpaceWithBasis(a): ModMatRngElt -> ModTupRng#
Given a sequence \(Q\) (or matrix \(a\)) of \(k\) independent vectors each lying in a module \(M\), construct the submodule of \(M\) of dimension \(k\) whose basis is \(Q\) (or the rows of \(a\)). The basis is echelonized internally but all functions which depend on the basis of the space (e.g.
Coordinates) will use the given basis.
- RMatrixSpaceWithBasis(Q): [ModTupRngElt] -> ModMatRng#
The module of \(m \times n\) matrices whose basis is given by the linearly independent matrices of the sequence \(Q\).